cengage / g tewani maths solutions chapter circles || coordinate geometry … · 2018. 12. 8. ·...

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CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY Download Doubtnut Today Ques No. Question 1 CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Definition Find the equation of the circle with radius 5 whose center lies on the x-axis and passes through the point (2, 3). Watch Free Video Solution on Doubtnut 2 CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Definition If the lines are diameters of the circle which passes through the point (2, 6), then find its equation. Watch Free Video Solution on Doubtnut 3 CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Definition Find the equation of the circle having center at (2,3) and which touches Watch Free Video Solution on Doubtnut 4 CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Definition Find the equation of the circle having radius 5 and which touches line at point (1, 2). Watch Free Video Solution on Doubtnut 5 CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Definition If represents the real circle with nonzero radius, then find the values of Watch Free Video Solution on Doubtnut x + y =6andx +2y =4 x + y =1 3 x +4 y − 11 = 0 x 2 + y 2 −2x +2 ay + a +3=0 a .

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Page 1: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

CENGAGE/GTEWANIMATHSSOLUTIONS

CHAPTERCIRCLES||COORDINATEGEOMETRY

DownloadDoubtnutToday

QuesNo. Question

1

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find the equation of the circle with radius 5 whose center lies on the x-axis andpassesthroughthepoint(2,3).

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2

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If the lines are diameters of the circle which passesthroughthepoint(2,6),thenfinditsequation.

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3

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findtheequationofthecirclehavingcenterat(2,3)andwhichtouches

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4

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find the equation of the circle having radius 5 and which touches lineatpoint(1,2).

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5

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If representstherealcirclewithnonzeroradius,thenfindthevaluesof

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x + y = 6andx + 2y = 4

x + y = 1

3x+ 4y − 11 = 0

x2 + y2 − 2x + 2ay + a + 3 = 0a.

Page 2: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

6

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find the image of the circle in the line

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7

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Theline istangenttothecircleatthepoint(2,5)andthecenterofthecirclelieson .Thenfindtheradiusofthecircle.

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8

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If the lines and are tangents toacircle, thenfindtheradiusofthecircle.

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9

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Iftheequation

representsacircle,thenfindthevaluesof

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10

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Apoint movesinsuchawaythattheratioofitsdistancefromtwocoplanarpointsisalwaysafixednumber .Then,identifythelocusofthepoint.

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x2 + y2 − 2x + 4y − 4 = 02x− 3y + 5 = 0

2x − y + 1 = 0x − 2y = 4

3x − 4y + 4 = 0 6x − 8y − 7 = 0

px2 + (2 − q)xy + 3y2 − 6qx+ 30y+ 6q = 0

pandq.

P( ≠ 1)

Page 3: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

11

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Provethatthemaximumnumberofpointswithrationalcoordinatesonacirclewhosecenteris istwo.

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12

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Prove that for all values of , the locus of the point of intersection of the linesand isacircle.

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13

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findthelengthofthechord alongtheline Alsofindtheanglethatthechordsubtendsatthecircumferenceofthelargersegment.

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14

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

LetA(-2,2)andB(2,-2)betwopointsABsubtendsanangleof atanypointsPintheplaneinsuchawaythatareaof is8squareunit,thennumberofpossibeposition(s)ofPis

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15

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Ifacirclepassesthroughthepoint ,thenfinditscenter.

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

(√3, 0)

θx cos θ+ y sin θ = a x sin θ − y cosθ = b

x2 + y2 − 4y = 0 x + y = 1.

45 ∘

ΔPAB

(0, 0), (a, 0)and(0, b)

(1, − 2), (4, − 3)

Page 4: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

16 Find theequationof thecirclewhichpasses through thepointsandwhosecenterliesontheline

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17

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Show that a cyclic quadrilateral is formed by the lines and taken in order. Find the

equationofthecircumcircle.

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18

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find theequationof the circle if the chordof the circle joining (1, 2) andsubtents atthecenterofthecircle.

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19

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find the equation of the circle which passes through (1, 0) and (0, 1) and has itsradiusassmallaspossible.

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(1, − 2), (4, − 3)3x + 4y = 7.

5x+ 3y = 9, x = 3y, 2x = y x + 4y + 2 = 0

( − 3, 1)900

Page 5: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

20

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If theabscissaandordinatesof twopoints are the roots of the equationsand , respectively, then find theequation

ofthecirclewith asdiameter.

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21

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Tangents are drawn to from the point Thenfindtheequationofthecircumcircleoftriangle

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22

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thepointonacirclenearesttothepoint isatadistanceof4unitsandthefarthestpointis(6,5).Thenfindtheequationofthecircle.

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23

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findtheparametricformoftheequationofthecircle

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24

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findthecenterofthecircle

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findthelengthof intercept,thecircle makesonthe

PandQx2 + 2ax− b2 = 0 x2 + 2px − q2 = 0

PQ

PAandPB x2 + y2 = a2 P (x1, y1).PAB.

P(2, 1)

x2 + y2 + px + py = 0.

x = − 1 + 2 cosθ, y = 3 + 2sin θ

x2 + y2 + 10x − 6y + 9 = 0

Page 6: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

25 x-axis.

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26

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If the intercepts of the variable circle on the x- and yl-axis are 2 units and 4 units,respectively,thenfindthelocusofthecenterofthevariablecircle.

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27

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Find the equation of the circle which touches both the axes and the straight lineinthefirstquadrantandliesbelowit.

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28

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Acircletouchesthey-axisatthepoint(0,4)andcutsthex-axisinachordoflength6units.Thenfindtheradiusofthecircle.

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29

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Find the equation of the circle which is touched by , has its center on thepositivedirectionof thex=axisandcutsoffachordof length2unitsalong the line

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle

4x+ 3y = 6

y = x

√3y − x = 0

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30

WithTypicalConditions

Findtheequationsofthecirclespassingthroughthepoint andtouchingthelines and

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31

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the greatest distance of the point from the circle

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32

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the points on the circle which are the farthestandnearesttothepoint

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33

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findthevaluesof forwhichthepoint liesinthelargersegmentofthe circle made by the chord whose equation is

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34

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find thenumberofpoint having integral coordinatessatisfying thecondition

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35

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Thecircle doesnottouchorintersectthecoordinateaxes,andthepoint(1,4)isinsidethecircle.Findtherangeofvalueof

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( − 4, 3)x + y = 2 x− y = 2

P(10, 7)x2 + y2 − 4x − 2y − 20 = 0

x2 + y2 − 2x + 4y − 20 = 0( − 5, 6).

α (α − 1, α + 1)x2 + y2 − x − y − 6 = 0

x + y − 2 = 0

(x, y)x2 + y2 < 25

x2 + y2 − 6x − 10y + k = 0k.

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36

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the area of the region in which the points satisfy the inequatiesand .

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37

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

If the line is a diameter of the circle ,thenfindthevalueof

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38

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Prove that the locusof thepoint thatmovessuch that thesumof thesquaresof itsdistancesfromthethreeverticesofatriangleisconstantisacircle.

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39

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the number of integral values of for which is theequationof a circlewhose radiusdoes

notexceed5.

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

4 < x2 + y2 < 16 3x2 − y2 ≥ 0

x + 2by + 7 = 0 x2 + y2 − 6x+ 2y = 0b

λx2 + y2 + λx + (1 − λ)y + 5 = 0

Page 9: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

40 Ifacirclewhosecenteris touchestheline ,thenfinditsradius.

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41

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Ifoneendof theadiameterof thecircle is (3,2),thenfindtheotherendofthediameter.

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42

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Prove that the locus of the centroid of the triangle whose vertices areand ,where isaparameter,iscircle.

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43

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the equation of the circle which passes through the pointsandthecenterliesontheline

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44

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findtheradiusofthecircle

.

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(1, − 3) 3x − 4y − 5 = 0

2x2 + 2y2 − 4x − 8y + 2 = 0

(a cos t, a sin t), (b sin t, − b cos t), (1, 0) t

(3, − 2)and( − 2, 0) 2x − y = 3

(x − 5)(x − 1) + (y − 7)(y − 4)= 0

Page 10: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

45

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findtheequationsof thecircleswhichpassthroughtheoriginandcutoffchordsoflength fromeachofthelines

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46

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findtheequationofthecirclewhichtouchesthex-axisandwhosecenteris(1,2).

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47

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findtheequationofthecirclewhichtouchesboththeaxesandtheline

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48

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findtheequationofthecirclewithcenterat andwhichcutsoffaninterceptoflength6fromtheline

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49

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findthelocusofthecenterofthecirclewhichcutsoffinterceptsoflengthsfromthex-andthey-axis,respectively.

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a y = xandy = − x

x = c

(3, − 1)2x − 5y + 18 = 0

2aand2b

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50

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Circlesaredrawnthroughthepoint (2,0) tocut interceptof length5unitson thex-axis.Iftheircenterslieinthefirstquadrant,thenfindtheirequation.

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51

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find the equation of the circle passing through the origin and cutting intercepts oflengths3unitsand4unitssfromthepositiveexes.

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52

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Find thepointof intersectionof thecircle with thex-axis.

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53

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Findthevaluesof forwhichthepoints lieonacircle.

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54

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Ifoneendofthediameteris(1,1)andtheotherendliesontheline ,thenfindthelocusofthecenterofthecircle.

x2 + y2 − 3x− 4y + 2 = 0

k (2k, 3k), (1, 0), (0, 1), and(0, 0)

x + y = 3

Page 12: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

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55

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Tangent drawn from the point to the circle touches it at thepoint in the first quadrant. Find the coordinates of another point on the circlesuchthat .

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56

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

If the joinof and makesonobtuseangle at thenprovethan

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57

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Find the range of values of for which the line cuts the circleatdistinctorcoincidentpoints.

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58

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Ifthelines and cutthecoordinaeaxesatconcyclicpoints,thenprovethat

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59

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

AlineisdrawnthroughafixpointP( )tocutthecircle atAandB.ThenPA.PBisequalto:

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P(4, 0) x2 + y2 = 8A BAB = 4

(x1, y1) (x2, y2) (x3, y3),

(x3 − x1)(x3 − x2) + (y3 − y1)(y3− y2) < 0

m y = mx + 2x2 + y2 = 1

a1x + b1y + c1 = 0 a2x+ b2y + c2 = 0|a1a2| = |b1b2|

α, β x2 + y2 = r2

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60

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Two circles intersect at two distinct points in a line passingthrough meetscircles at ,respectively.Let bethemidpointof

meetscircles at , respectively.Thenprovethatisthemidpointof

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61

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Find the angle between the two tangents from the origin to the circle

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62

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Findtheequationsofthetangentstothecircle whichareparalleltothestraightline

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63

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Find the equation of the tangent at the endpoints of the diameter of circlewhichisinclinedatanangle withthepositivex-axis.

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

C1andC2 PandQP C1andC2 AandB Y

AB, andQY C1andC2 XandZ YXZ .

(x − 7)2 + (y + 1)2 = 25

x2 + y2 − 6x + 4y = 124x + 3y + 5 = 0

(x − a)2 + (y − b)2 = r2 θ

2 2

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64 The tangent to the circle at also touches the circle . Find the coordinats of the corresponding point of

contact.

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65

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Provethattheequationofanytangenttothecircle isoftheform

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66

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

If thenfindthepositivevalueof forwhich isacommontangentto and

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67

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Provethattheanglebetweenthetangentsfrom tothecircle is

,where

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68

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Thelengthsofthetangentsfrom and toacircleare and ,respectively. Then, find the length of the tangent from to the samecircle.

x2 + y2 = 5 (1, − 2)x2 + y2 − 8x + 6y + 20 = 0

x2 + y2 − 2x + 4y − 4 = 0y = m(x− 1) + 3√1 + m2 − 2.

a > 2b > 0, m y = mx − b√1 + m2

x2 + y2 = b2 (x − a)2 + y2 = b2.

(α, β) x2 + y2 = a2

2 tan−1( )a

√S1S1 = α2 + β2 − a2

P(1, − 1) Q(3, 3) √2 √6R( − 1, − 5)

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69

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

If from any point on the circle tangents aredrawntothecircle

,thenfindtheanglebetweenthetangents.

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70

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Ifthedistancesfromtheoriginofthecentersofthreecircles

areinGP,thenprovethatthelengthsofthetangentsdrawntothemfromanypointonthecircle areinGP.

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71

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Findtheequationof thenormalstothecircle at thepointwhoseordinateis

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72

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Find theequationof thenormal to thecircle parallel to the line

P x2 + y2 + 2gx+ 2fy + c = 0,

x2 + y2 + 2gx + 2fy + c sin2α

+ (g 2 + f2)cos2α = 0

x2 + y2 + 2λx − c2 = 0,(i = 1, 2, 3),

x2 + y2 = c2

x2 + y2 − 8x − 2y + 12 = 0−1

x2 + y2 − 2x = 0x + 2y = 3.

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73

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Find the equation of the tangent to the circle whichmakesequalinterceptsonthepositivecoordinatesaxes.

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74

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

If the length tangent drawn from the point (5, 3) to the circleis7,thenfindthevalueof

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75

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

A pair of tangents are drawn from the origin to the circle.Thenfinditsequations.

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76

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Findtheequationofthenormaltothecircle atthepoint

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77

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Find the equations of tangents to the circle whichareperpendiculartotheline

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x2 + y2 + 4x − 4y + 4 = 0

x2 + y2 + 2x + ky + 17 = 0 k.

x2 + y2 + 20(x + y) + 20 = 0

x2 + y2 = 9 ( , )1

√2

1

√2

x2 + y2 − 22x − 4y + 25 = 05x + 12y + 8 = 0

Page 17: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

78

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

An infinite number of tangents can be drawn from to the circle.Thenfindthevalueof

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79

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

If thecircle intersects the line at twodistinctpoints,thenfindthevaluesof

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80

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

If a line passing through theorigin touches the circle ,thenfinditsslope.

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81

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Thetangentatanypoint onthecircle meetsthecoordinateaxesat.Thenfindthelocusofthemidpointof

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82

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Findthelocusofapointwhichmovessothattheratioofthelengthsofthetangentstothecircles and is

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(1, 2)x2 + y2 − 2x − 4y + λ = 0 λ

x2 + y2 − 4x − 8y − 5 = 0 3x − 4y = mm.

(x− 4)2 + (y + 5)2 = 25

P x2 + y2 = 4AandB AB.

x2 + y2 + 4x+ 3 = 0 x2 + y2 − 6x + 5 = 0 2 : 3.

Page 18: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

83

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Find the length of the tangent drawn from any point on the circletothecircle

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84

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Find the ratio of the length of the tangents from any point on the circle to the two circles

and

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85

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

If the chord of contact of the tangents drawn from a point on the circle to the circle touches the circle ,

thenprovethat and areinGP.

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86

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

If the straight line intersects the circle at point,thenfindthecoordinatesofthepointofintersectionofthetangentsdrawn

at tothecircle

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

x2 + y2 + 2gx + 2fy + c1 = 0 x2 + y2 + 2gx + 2fy + c2 = 0

15x2 + 15y2 − 48x+ 64y = 05x2 + 5y2 − 24x+ 32y + 75 = 0 5x2 + 5y2 − 48x + 64y + 300 = 0

x2 + y2 + y2 = a2 x2 + y2 = b2 x2 + y2 = c2

a, b c

x = 2y + 1 = 0 x2 + y2 = 25PandQPandQ x2 + y2 = 25.

( , )

Page 19: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

87If the chord of contact of the tangents drawn from the point to the circle

subtendsarightangleatthecenter,thenprovethat

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88

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Tangents are drawn to from any arbitrary point on the line .Thecorrespondingchordofcontactpassesthroughafixedpoint

whosecoordinatesare (b) (d)

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89

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Findtheareaofthetriangleformedbythetangentsfromthepoint(4,3)tothecircleandthelinejoiningtheirpointsofcontact.

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90

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Find the equation of the chord of the circle whose middle point is

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91

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Avariablechordisdrawnthroughtheorigintothecircle .Findthelocusofthecenterofthecircledrawnonthischordasdiameter.

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(h, k)x2 + y2 = a2 h2 + k2 = 2a2.

x2 + y2 = 1 P2x+ y − 4 = 0

( , )12

12

( , 1)12

( , )12

14

(1, )12

x2 + y2 = 9

x2 + y2 = 9(1, − 2)

x2 + y2 − 2ax = 0

Page 20: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

92

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Findtheequationofthechordofthecircle passingthroughthepoint(2,3)farthestfromthecenter.

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93

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Findthemiddlepointofthechordofthecircle interceptedontheline

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94

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Theline isthechordofcontactofthepoint withrespect

tothecircle , for(a) (b) (c)

(d)

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95

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Tangentsaredrawn to the circle at the pointswhere it ismet by thecircle .Finthepointofintersectionofthesetangents.

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

x2 + y2 = a2

x2 + y2 = 25x − 2y = 2

9x + y − 18 = 0 P(h, k)

2x2 + 2y2 − 3x + 5y − 7 = 0 ( , − )245

45

P(3, 1)

P( − 3, 1) ( − , )25

125

x2 + y2 = 9x2 + y2 + 3x + 4y + 2 = 0

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96 The distance between the chords of contact of tangents to the circlefromtheorigin&thepoint(g,f)is

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97

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Find the number of common tangent to the circlesand

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98

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Findtheequationofacirclewithcenter(4,3)touchingthecircle

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99

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Find the condition if the circle whose equations are andtouchoneanotherexternally.

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100

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Findtheequationofthesmallcirclethattouchesthecircle andpassesthroughthepoint

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101

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Show that the circles andtoucheachother.Findthecoordinatesofthepoint

ofcontactandtheequationofthecommontangentatthepointofcontact.

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x2 + y2 + 2gx + 2fy + c = 0

x2 + y2 + 2x + 8y − 23 = 0x2 + y2 − 4x − 10y + 9 = 0

x2 + y2 = 1

x2 + y2 + c2 = 2axx2 + y2 + c2 − 2by = 0

x2 + y2 = 1(4, 3).

x2 + y2 − 10x+ 4y − 20 = 0x2 + y2 + 14x− 6y + 22 = 0

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102

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Find the equations to the common tangents of the circlesand

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103

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

If the circles and intersect othrogonally, then prove that +

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104

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

A circle passes through the origin and has its center on If it cutsorthogonally,thenfindtheequationofthecircle.

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105

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

If the radical axis of the circles andtouchesthecircle ,show

thateither or

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Theequationofthreecirclesaregiven

x2 + y2 − 2x − 6y + 9 = 0 x2 + y2 + 6x − 2y + 1 = 0

x2 + y2 + 2a ′x + 2b ′y + c ′ = 02x2 + 2y2 + 2ax + 2by + c = 0 aa ′ bb

' = c + .c ′

2

y = xx2 + y2 − 4x − 6y + 10 = −

x2 + y2 + 2gx + 2fy + c = 02x2 + 2y2 + 3x + 8y + 2c = 0 x2 + y2 + 2x + 1 = 0

g =34

f = 2

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106

.Determinethecoordinatesofthepoint suchthatthetangentsdrawnfromittothecircleareequalinlength.

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107

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Findtheequationofthecirclewhichcutsthethreecircles

and orthogonally.

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108

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Ifthetangentsaredrawntothecircle atthepointwhereitmeetsthecircle then find the point of intersection of thesetangents.

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109

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Find theanglewhich thecommonchordof andsubtendsattheorigin.

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Find the length of the common chord of the circles and

x2 + y2 = 1, x2 + y2 − 8x + 15

= 0, x2 + y2 + 10y + 24 = 0P

x2 + y2 − 3x − 6y + 14 = 0, x2

+ y2 − x − 4y + 8 = 0,x2 + y2 + 2x − 6y + 9 = 0

x2 + y2 = 12x2 + y2 − 5x + 3y − 2 = 0,

x2 + y2 − 4x = 0 x2 + y2 = 16

x2 + y2 + 2x + 6y = 02 2

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110

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111

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If thecircle bisects thecircumferenceof thecirclethenprovethat

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112

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Provethatthepairofstraightlinesjoiningtheorigintothepointsofintersectionofthecircles and is

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113

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If the circle is completely contained in the circle,thenfindthevaluesof

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If istheanglebetweenthetworadii(onetoeachcircle)drawnfromoneofthepoint

x2 + y2 − 4x − 2y − 6 = 0

x2 + y2 + 2gx + 2fy + c = 0x2 + y2 + 2g ′ x+ 2f ′ y + c ′ = 02g ′(g − g ′) + 2f ′ (f − f ′ ) = c

− c'

x2 + y2 = a x2 + y2 + 2(gx + fy) = 0a ′ (x2 + y2) − 4(gx+ fy)2 = 0

x2 + y2 = 1x2 + y2 + 4x + 3y + k = 0 k.

θ2 2 2 2 2 2

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114 of intersection of two circles and then prove

thatthelengthofthecommonchordofthetwocirclesis

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115

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Thecircles and toucheachotherexternallytoucheachotherinternallyintersectattwopointsnoneofthese

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116

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If the circles andintersects at points P and Q , then find the values of for which the line

passesthrough

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117

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Which of the following is a point on the common chord of the circle and (b)

(d)

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118

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Considerthecircles

They are such that these circles touch each other one of these circles lies entirelyinsidetheothereachofthesecirclesliesoutsidetheothertheyintersectattwopoints.

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119

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If thecirclesofsameradius andcentersat (2,3)and5,6)cutorthogonally, thenfind

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x2 + y2 = a2 (x − c)2 + y2 = b2,2ab sin θ

√a2 + b2 − 2ab cosθ

x2 + y2 − 12x − 12y = 0 x2 + y2 + 6x + 6y = 0.

x2 + y2 + 2ax + cy + a = 0 x2 + y2 − 3ax + dy − 1 = 0a

5x+ by − a = 0 PandQ.

x2 + y2 + 2x − 3y + 6 = 0 x2 + y2 + x − 8y − 31 = 0? (1, − 2)(1, 4) (1, 2) 1, 4)

x2 + (y − 1)2 = 9, (x − 1)2 + y2

= 25.

aa.

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120

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If the two circles andcutorthogonally,thenfindthevalueof .

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121

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Find the condition that the circle lies entirelywithin thecircle .

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122

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Findtheradicalcenterofthecircles

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Two circles and intersect in such a way that their common chord is of

2x2 + 2y2 − 3x + 6y + k = 0x2 + y2 − 4x + 10y + 16 = 0 k

(x− 3)2 + (y − 4)2 = r2

x2 + y2 = R2

x2 + y2 + 4x + 6y = 19, x2 + y2

= 9, x2 + y2 − 2x − 4y = 5,

C1 C2

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123 maximumlength.Thecenterof is(1,2)anditsradiusis3units.Theradiusof

is5units.Iftheslopeofthecommonchordis thenfindthecenterof

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124

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

The equation of a circle is Find the center of the smallest circletouchingthecircleandtheline

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125

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Consider four circles . Find the equation of the smallercircletouchingthesefourcircles.

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126

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Find the equation of the circle whose radius is 3 and which touches internally thecircle atthepoint

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127

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Find the number of common tangents that can be drawn to the circlesand

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C1 C2

,34

C2 .

x2 + y2 = 4.x + y = 5√2

(x± 1)2 + (y ± 1)2 = 1

x2 + y2 − 4x − 6y = − 12 = 0 ( − 1, − 1).

x2 + y2 − 4x − 6y − 3 = 0 x2 + y2 + 2x + 2y + 1 = 0

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128

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Two fixed circles with radii , respectively, touch each otherexternally.Thenidentifythelocusofthepointofintersectionoftheirdirectioncommontangents.

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129

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Two circles with radii touch each other externally such that is the anglebetween the direct common tangents, . Then prove that

.

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130

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If the radii of the circles andareincreasinguniformlyw.r.t. timeas0.3units/sand0.4

unit/s,respectively,thenatwhatvalueof willtheytoucheachother?

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131

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

If the circle cuts at,thenfindtheequationofthecircleon asdiameter.

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r1andr2, (r1 > r2)

aandb θ(a > b ≥ 2)

θ = 2 sin−1( )a − ba + b

(x − 1)2 + (y − 2)2 + (y − 2)2 = 1( − 7)2 + (y − 10)2 = 4

t

x2 + y2 + 2x + 3y + 1 = 0 x2 + y2 + 4x+ 3y + 2 = 0AandB AB

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132

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Show that the equation of the circle passing through (1, 1) and the points ofintersection of the circles and

is

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133

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Find the equation of the smallest circle passing through the intersection of the lineandthecircle

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134

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

and arecircleofunitradiuswithcentersat(0,0)and(1,0),respectively, isacircleofunitradius.Itpassesthroughthecentersofthecircles andhasits center above the x-axis. Find the equation of the common tangent towhichdoesnotpassthrough

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135

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Findtheradiusof thesmallestcirclewhichtouchesthestraight line atandalsotouchestheline .Computeuptooneplaceofdecimalonly.

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136

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Avariablecirclewhichalwaystouchestheline at(1,1)cutsthecircle . Prove that all the common chords of intersection

passthroughafixedpoint.Findthatpoints.

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137

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Let be a circle passing through and and be a circle ofradius unitssuchthat isthecommonchordof Findtheequationof

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x2 + y2 + 13x − 13y = 02x2 + 2y2 + 4x − 7y − 25 = 0 4x2 + 4y2 + 30x − 13y − 25 = 0.

x + y = 1 x2 + y2 = 9

C1 C2 C3C1andC2

C1andC3C2.

3x− y = 6(1, − 3) y = x

x + y − 2 = 0x2 + y2 + 4x + 5y − 6 = 0

S1 A(0, 1) B( − 2, 2) S2√10 AB S1andS2.

S2 .

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138

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

If belongtoafamilyofcirclesthroughthepointsprovethattheratioofthelengthofthetangentsfromanypointon tothecircles

isconstant.

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139

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Provethatquadrilateral ,where

isconcyclic.Alsofindtheequationofthecircumcircleof

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140

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Ifalinesegement movesintheplane remainingparallelto sothattheleftendpoint slidesalongthecircle thenthelocusof

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141

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

The tangents to having inclinations and intersect at If,thenfindthelocusof

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

C1, C2, andC3 (x1, y2)and(x2, y2)C1

C2andC3

ABCDAB ≡ x + y − 10,BC ≡ x − 7y+ 50 = 0, CD ≡ 22x − 4y + 125= 0, andDA ≡ 2x − 4y − 5 = 0,

ABCD.

AM = a XOY OXA x2 + y2 = a2, M .

x2 + y2 = a2 α β P .cotα + cot β = 0 P .

2 2 2

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142 The locusof thepoint of intersectionof the tangents to the circle atpointswhoseparametricanglesdifferby .

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143

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Findthelocusofthecenterofthecircletouchingthecircleinternallyandtangentsonwhichfrom(1,2)aremakingof witheachother.

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144

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Tworodsoflengths slidealongthe and respectively,insuchamannerthattheirendsareconcyclic.Findthelocusofthecenterofthecirclepassingthroughtheendpoints.

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145

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

A circle with center at the origin and radius equal to a meets the axis of atand aretwopointsonthecirclesothat ,where is

aconstant.Findthelocusofthepointofintersectionof and

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146

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Findthelocusofthemidpointofthechordsofthecircle whichsubtendarightangleatthepoint

x2 + y2 = a2π

3

x2 + y2 − 4y − 2x = 4600

aandb x − y − aξs,

x

AandB.P(α) Q(β) α − β = 2y γ

AP BQ.

x2 + y2 = a2

(c, 0).

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147

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Avariablecirclepassesthroughthepoint andtouchesthex-axis.Showthatthelocusoftheotherendofthediameterthrough is

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148

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Find the locusof themidpoint of the chordof the circle ,whichmakesanangleof atthecenter.

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149

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

A tangent is drawn to each of the circles and Showthat if the two tangents are mutually perpendicular, the locus of their point ofintersectionisacircleconcentricwiththegivencircles.

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150

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

The circle is inscribed in a variable triangleSides and lie along the x- andy-axis, respectively,where is the origin.Findthelocusofthemidpointofside

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based On

A(a, b)A (x− a)2 = 4by.

x2 + y2 − 2x − 2y = 01200

x2 + y2 = a2 x2 + y2 = b2 .

x2 + y2 − 4x − 4y + 4 = 0 OAB.OA OB O

AB.

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151

Locus

Apointmovessothatthesumofthesquaresoftheperpendicularsletfallfromitonthesidesofanequilateraltriangleisconstant.Provethatitslocusisacircle.

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152

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

isthevariablepointonthecirclewithcenterat and areperpendicularsfrom onthex-andthey-axis, respectively.Showthat the locusof thecentroidoftriangle isacirclewithcenteratthecentroidoftriangle andradiusequaltotheone-thirdoftheradiusofthegivencircle.

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153

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Tangents are drawn to the circle from two points on the axis ofequidistant from the point Show that the locus of their intersection is

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154

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Astraightlinemovessothattheproductofthelengthoftheperpendicularsonitfromtwofixedpointsisconstant.Provethatthelocusofthefeetoftheperpendicularsfromeachofthesepointsuponthestraightlineisauniquecircle.

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155

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Findthelocusofcenterofcircleofradius2units,ifinterceptcutonthex-axisistwiceofinterceptcutonthey-axisbythecircle.

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P C.CA CB

CPAB CAB

x2 + y2 = a2 x,(k, 0).

ky2 = a2(k − x).

Page 34: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

156

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

ABCDisarectangle.AcirclepassingthroughvertexCtouchesthesidesABandADatMandN respectively. If thedistance lof the lineMN from thevertexC isPunitsthentheareaofrectangleABCDis

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157

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Let beatriangleright-angledat beitscircumcircle.Let bethecircletouchingthelines and andthecircle internally.Further,let bethecircletouchingthelines and producedandthecircle externally.If and aretheradiiofthecircles and ,respectively,showthat area

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158

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Therangeofparameter forwhichthevariableline liesbetweenthecircles and withoutintersecting or touching either circle is

(d)

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159

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Findthelocusofthecentersofthecircles ,whereand are parameters, if the tangents from the origin to each of the circles areorthogonal.

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

ABC AandS S1AB AC S S2AB AC S r1 r2S1 S2 r1r2 = 4 (ABC).

' a' y = 2x+ ax2 + y2 − 2x − 2y + 1 = 0 x2 + y2 − 16x− 2y + 61 = 0

a ∈ (2√5 − 15, 0)a ∈ ( − ∞, 2√5 − 15, ) a ∈ (0, − √5 − 10) a ∈ ( −√5 − 1,∞)

x2 + y2 − 2ax− 2by + 2 = 0 ab

2 2

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160(C) 2 45. Three concentric circles of which the biggest is , have theirradii inA.P If the line cutsall thecircles in realanddistinctpoints.TheintervalinwhichthecommondifferenceoftheA.Pwilllieis:

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161

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Let and beanylinepassingthrough(4,1)havingslope Find therangeof forwhichthereexist twopointson atwhichsubtendsarightangle.

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162

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Theequationof radicalaxisof twocircles is .Oneof thecircleshas theendsofadiameteratthepoints and theotherpasses throughthepoint(1,2).Findtheequatingofthesecircles.

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163

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

isacirclehavingthecenterat andradius`b(bWatchFreeVideoSolutiononDoubtnut

164

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

represents a circle. The equation gives two identicalsolutions: .Theequation giventwosolutions: Findtheequationofthecircle.

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x2 + y2 = 1y = x+ 1

A ≡ ( − 1, 0), B ≡ (3, 0), PQm. m PQ AB

x + y = 1(1, − 3) and (4, 1)

S (0, a)

S(x, y) = 0 S(x, 2) = 0x = 1 S(1, y) = 0 y = 0, 2.

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165

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Findtheequationofthefamilyofcirclestouchingthelines

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166

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

are two points in the xy-plane, which are units distance apart andsubtendanangleof at thepoint on the line ,which islarger thananyanglesubtendedby the linesegment atanyotherpointon theline.Findtheequation(s)ofthecirclethroughthepoints

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167

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Fromthevariablepoint oncircle two tangentsaredrawn to thecircle which meet the curve at Find the locus of thecircumcenterof

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168

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Findthecircleofminimumradiuswhichpassesthroughthepoint(4,3)andtouchesthecircle externally.

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Two variable chords of a circle are such that

x2 − y2 + 2y − 1 = 0.

AandB 2√2900 C(1, 2) x − y + 1 = 0

ABA, BandC .

A x2 + y2 = 2a2,x2 + y2 = a2 BandC.

ABC .

x2 + y2 = 4

ABandBC x2 + y2 = r2

= =

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169 .Findthelocusofthepointofintersectionoftangentsat

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170

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

If is a tangent to a circle whose center is , then find theequationoftheothertangenttothecirclefromtheorigin.

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171

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Findthelengthofthechordofcontactwithrespecttothepointonthedirectorcircleofcircle .

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172

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Acircle is thedirectorcircleofcircle ,isthedirectorcircleofcircle ,andsoon.Ifthesumofradiiofallthesecirclesis2,thenfindthevalueofc.

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173

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Consider three circles such that is the director circle of is the director circlé of . Tangents to , from any point on

intersect ,at .Findtheanglebetweenthetangentsto atPandQ.Alsoidentifythelocusofthepointofintersec-tionoftangentsat .

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AB = BC = r AandC .

3x + y = 0 (2, − 1)

x2 + y2 + 2ax − 2by + a2 − b2 = 0

x2 + y2 + 4x − 2√2y + c = 0 S1 and S2S1

C1,C2 and C3 C2C1, and C3 C2 C1 C3

C2 P 2 and Q C22

P and Q

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174

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

From a point on the normal of the circle two tangents are drawn to the same circle

touching it at point . If the area of quadrilateral (where is thecenterofthecircle)is36sq.units,findthepossiblevaluesof Itisgiventhatpointisatdistance fromthecircle.

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175

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Find the center of the smallest circle which cuts circles andorthogonally.

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176

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Perpendiculars are drawn, respectively, from the points to the chords ofcontact of the points with respect to a circle. Prove that the ratio of thelengthsofperpendiculars isequaltotheratioofthedistancesofthepointsfromthecenterofthecircles.

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177

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Thenumber of suchpoints ,where a is any integer, lying inside theregion bounded by the circles and

,is

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178

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

If eight distinct points can be found on the curve such that fromeachpoint two mutually perpendicular tangents can be drawn to the circle

thenfindthetangeof

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P y = x+ cx2 + y2 − 2x − 4y + 5 − λ2 − 0,

BandC OBPC Oλ. P

|λ|(√2 − 1)

x2 + y2 = 1x2 + y2 + 8x + 8y − 33 = 0

PandQQandP

PandQ

(a + 1, √3a)x2 + y2 − 2x − 3 = 0

x2 + y2 − 2x − 15 = 0

|x| + |y| = 1

x2 + y2 = a2, a.

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179

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Acircleofradius5unitshasdiameteralongtheanglebisectorofthelinesand If thechordofcontact fromtheoriginmakesanangleof withthepositivedirectionofthex-axis,findtheequationofthecircle.

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180

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Let bechordofcontactofthepoint w.r.tthecircle .Thenfindthelocusoftheorthocentreofthetriangle ,where isanypointmovingonthecircle.

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181

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Let be anymoving point on the circle be the chord ofcontact of this point w.r.t. the circle . The locus of thecircumcenter of triangle being the center of the circle) is

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182

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

AB is a diameter of a circle. CD is a chord parallel to AB and . ThetangentatBmeetsthelineACproducedatEthenAEisequalto-

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

x + y = 2x − y = 2. 450

AB (5, − 5) x2 + y2 = 5PAB P

P x2 + y2 − 2x = 1. ABx2 + y2 − 2x = 0

CAB(C2x2 + 2y2 − 4x + 1 = 0 x2 + y2 − 4x + 2 = 0 x2 + y2 − 4x + 1 = 02x2 + 2y2 − 4x + 3 = 0

2CD = AB

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183Twoparalleltangentstoagivencirclearecutbyathirdtangentatthepoint .Show that the lines from to the center of the circle are mutuallyperpendicular.

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184

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Acircleofradius1unittouchesthepositivex-axisandthepositivey-axisat ,respectively. A variable line passing through the origin intersects the circle at twopoints .Iftheareaoftriangle ismaximumwhentheslopeofthelineis

thenfindthevalueof

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185

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

The number of rational point(s) [a point (a, b) is called rational, if both arerationalnumbers]onthecircumferenceofacirclehavingcenter isatmostone(b)atleasttwoexactlytwo(d)infinite

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186

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

If the equation of any two diagonals of a regular pentagon belongs to the family oflines andtheir lengthsaresin , thenthelocusofthecenterofcirclecircumscribingthegivenpentagon(thetrianglesformedbythesediagonalswiththesidesofpentagonhavenosidecommon)is

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RandQRandQ

AandB

DandE DEBm, m−2

aandb(π, e)

(1 + 2λ)λ − (2 + λ)x + 1 − λ = 0 360

x2 + y2 − 2x − 2y + 1 + sin2 720

= 0x2 + y2 − 2x − 2y + cos2 720 = 0x2 + y2 − 2x − 2y + 1 + cos2 720

= 0x2 + y2 − 2x − 2y + sin2 720 = 0

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187

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If are equal perpendicular chords of the circles , then the equations of are,where is the

origin. and and and and

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188

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Theequationofthechordofthecircle ,whichpassesthroughtheoriginsuchthattheorigindividesitintheratio4:1,is

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189

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Theline istangenttothecircleatthepoint(2,5)andthecenterofthecirclelieson Theradiusofthecircleis (b) (c) (d)

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190

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Ina triangle rightangledat on the leg asdiameter,a semicircle isdescribed. Ifachord joins with thepointof intersection of thehypotenuseand

thesemicircle, then the lengthof isequal to (b)

(d)

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191

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

A rhombus is inscribed in the region common to the two circles and with two of its vertices on

thelinejoiningthecentersofthecircles.Theareoftherhombusis (b) (d)noneofthese

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OAandOBx2 + y2 − 2x + 4y = 0 OAandOB O

3x + y = 0 3x − y = 0 3x + y = 0 3y − x = 0 x + 3y = 0y − 3x = 0 x + y = 0 x − y = 0

x2 + y2 − 3x − 4y − 4 = 0

2x − y + 1 = 0x − 2y = 4. 3√5 5√3 2√5

5√2

ABC, A, ACA D

ACAB

.AD

√AB2 + AD2

AB.AD

AB + AD

√AB .AD

AB.AD

√AB2 − AD2

x2 + y2 − 4x − 12 = 0 x2 + y2 + 4x − 12 = 08√3sq

.units

4√3sq.units 6√3sq

.units

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192

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Thelocusfothecenterof thecirclessuchthatthepoint(2,3) isthemidpointof thechord is (a) (b) (c)

(d)noneofthese

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193

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Twocongruentcircleswithcenteredat(2,3)and(5,6)whichintersectatrightangles,haveradiusequalto2 (b)3(c)4(d)noneofthese

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194

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Acircleofradiusunityiscenteredatthetorigin.Twoparticlestartmovingatthesametimefromthepoint andmovearoundthecircleinoppositedirection.Oneoftheparticlemoves anticlockwisewith constant speed and the othermoves clockwisewithconstantspeed .Afterleaving ,thetwoparticlesmeetfirstatapointandcontinueuntiltheymeetnextatpoint .Thecoordinatesofthepoint are

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195

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Thevalueof'c'forwhichtheset

containsonlyonepointincommonis

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

5x + 2y = 16 2x − 5y + 11 = 0 2x + 5y − 11 = 02x+ 5y + 11 = 0

√3

(1, 0)v

3v (1, 0) P ,Q Q

{(x, y) ∣ x2 + y2 + 2x ≤ 1}

∩ {(x, y) ∣ x − y + c ≤ 0}

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196

Acircleisinscribedti.e.touchesallfoursides)intoarhombousABCDwithoneangle60°.Thedistancefromthecentreofthecircletothenearestvertexisequalto1.IfPisanypointofthecirclethen isequalto:

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197

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Two circles with radii touch each other externally such that is the anglebetween the direct common tangents, . Then prove that

.

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198

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

arefixedpointshavingcoordinates(3,0)and respectively.Iftheverticalangle is ,thenthelocusofthecentroidof hasequation.(a)

(b) (c) (d)

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199

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

is a square of unit area. A circle is tangent to two sides of andpasses through exactly one of its vertices. The radius of the circle is (b)

(d)

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

|PA|2 + |PB|2 + |PC|2 + |PD|2

aandb θ(a > b ≥ 2)

θ = 2 sin−1( )a − ba + b

BandC ( − 3, 0),BAC 900 ABC

x2 + y2 = 1 x2 + y2 = 2 9(x2 + y2) = 1 9(x2 + y2) = 4

ABCD ABCD2 − √2

√2 − 1 1/21

√2

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200

Apairoftangentsisdrawntoaunitcirclewithcenterattheoriginandthesetangentsintersectat enclosinganangleof .Theareaenclosedbythesetangentsand

thearcofthecircleis (b) (d)

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201

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

A straight line with slope 2 and y-intercept 5 touches the circle at a point Then the coordinates of are

(b) (d)

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202

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

A circle of constant radius passes through the origin and cuts the axes ofcoordinates at points and . Then the equation of the locus of the foot of

perpendicular from to is

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203

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

A linemeets the coordinate axes at and . A circle is circumscribed about thetriangle If aredistancesof thetangentstothecircleat theorigin

fromthepoints ,respectively,thenthediameterofthecircleis (b)

(d)

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A 600

−2

√3

π

6√3 −

π

3−

π

3√36

√3(1 − )π6

x2 + y2 + 16x+ 12y + c = 0 Q. Q( − 6, 11) ( − 9, − 13) ( − 10, − 15) ( − 6, − 7)

a OP Q

O PQ (x2 + y2)( + ) = 4a21

x21y2

(x2 + y2)2( + ) = a2

1

x21y2

(x2 + y2)2( + ) = 4a2

1

x21y2

(x2 + y2)( + ) = a21

x21y2

A BOAB. d1andd2 O

AandB2d1 + d2

2d1 + 2d2

2d1 + d2

d1d2

d1 + d2

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204

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Ifacircleofconstantradius passesthroughtheorigin andmeetsthecoordinateaxes at , then the locus of the centroud of triangle is (a)

(b) (c) (d)

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205

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Theequationofthelineinclinedatanangleof tothe suchthatthetwo

circles and interceptequallengthonit,is (b) (d)

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206

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Let be a circle with two diameters intersecting at an angle of A circle istangenttoboththediametersandto andhasradiusunity.Thelargestradiusofis (b) (d)noneofthese

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207

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

A straight line with equation meets the circle with equationat inthefirstquadrant.Alinethrough perpendicular to cuts

they-axisat .Thevalueof is12(b)15(c)20(d)25

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208

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Let representthelengthsofarighttriangleslegs.If isthediameterofacircleinscribed into the triangle, and is the diameter of a circle circumscribed on the

3k OAandB OAB

x2 + y2 = (2k)2 x2 + y2 = (3k)2 x2 + y2 = (4k)2 x2 + y2 = (6k)2

π

4X − aξs,

x2 + y2 = 4 x2 + y210x − 14y + 65 = 02x − 2y − 3 = 0 2x − 2y + 3 = 0 x − y + 6 = 0 x − y − 6 = 0

C 300 . SC C

1 + √6 + √2 1 + √6 −√2 √6 + √2 − 11

l1 x − 2y + 10 = 0x2 + y2 = 100 B B l1

P(o, t) t

aandb dD

1

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triangle,the equals.(a) (b) (c) (d)

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209

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Ifthechord ofthecircles subtendsanangleof atthemajorsegmentofthecircle,thenthevalueof is (b) (c) (d)noneofthese

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210

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Avariablechordofthecircle isdrawnfromthepoint meetingthe circle at the point and A point is taken on the chord such that

. The locus of is

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211

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

In triangle , the equation of side is The circumcenter andorthocentre of triangle are (2, 3) and (5, 8), respectively. The equation of thecircumcirle of the triangle is

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212

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

The range of values of r for which the point is an

interior point of themajor segment of the circle , cut-off by the line

d + D a + b 2(a + b) (a + b)12

√a2 + b2

y = mx + 1 x2 + y2 = 1 450m 2 −2 −1

x2 + y2 = 4 P (3, 5)A B. Q

2PQ = PA + PB Q x2 + y2 + 3x + 4y = 0 x2 + y2 = 36x2 + y2 = 16 x2 + y2 − 3x− 5y = 0

ABC BC x − y = 0.

x2 + y2 − 4x + 6y − 27 = 0x2 + y2 − 4x − 6y − 27 = 0 x2 + y2 + 4x+ 6y − 27 = 0x2 + y2 + 4x + 6y − 27 = 0

( − 5 + , − 3 + )r

√2

r

√2x2 + y2 = 16

+ = 2

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,is:

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213

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

A square is inscribed in the circle with its sidesparalleltothecoordinateaxes.Thecoordinatesofitsverticesare

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214

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

aretheverticesofa .Theincircleofthetrianglehas equation.

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215

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If is the origin and are the tangents from the origin to the circle , thenthecircumcenterof triangle is

(b) (d)

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x + y = 2

x2 + y2 − 2x + 4y − 93 = 0

( − 6, − 9), ( − 6, 5), (8, − 9),

(8, 5)( − 6, − 9), ( − 6, − 5), (8, − 9),

(8, 5)( − 6, − 9), ( − 6, 5), (8, 9), (8, 5)( − 6, − 9), ( − 6, 5), (8, − 9),

(8, − 5)

( − 6, 0), 0, 6), and( − 7, 7) ABC

x2 + y2 − 9x− 9y + 36 = 0 x2 + y2 + 9x − 9y + 36 = 0x2 + y2 + 9x + 9y − 36 = 0 x2 + y2 + 18x − 18y + 36 = 0

O OPandOQx2 + y2 − 6x + 4y + 8 − 0 OPQ (3, − 2)

( , − 1)32

( , − )34

12

( − , 1)32

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216

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Thelocusofthemidpointofalinesegmentthatisdrawnfromagivenexternalpointtoagivencirclewithcenter (where istheorgin)andradius isastraightline

perpendiculat to acirclewithcenter andradius acirclewithcenter andradius acirclewithcenteratthemidpoint andradius

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217

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Thedifferencebetween theradiiof the largestandsmallestcircleswhichhave theircentresonthecircumferenceofthecircle andpassesthroughpoint(a,b)lyingoutsidethecircleis:

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218

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Anisoscelestriangle isinscribedinacircle withthevertex at and the base angle each equal . Then the coordinates of an

endpoint of the base are. (b) (d)

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219

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Theequationof four circlesare .The radiusofacircletouchingallthefourcirclesis (b) (d)

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220

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thelocusofapointwhichmovessuchthatthesumofthesquareofitsdistancefromthreeverticesofatriangleisconstantisa/ancircle(b)straightline(c)ellipse(d)noneofthese

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

P O O rPO P r P

2r PO .r

2

x2 + y2 + 2x + 4y − 4 = 0

ABC x2 + y2 = a2 A

(a, 0) BandC 750

( − , )√3a2

a

2( − , a)√3a

2( , )a

2√3a2

( , − )√3a2

a

2

(x ± a)2 + (y ± a2 = a2

(√2 + 2)a 2√2a (√2 + 1)a (2 + √2)a

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221Acircle passes through thepoints and touches the y-axis at

If is maximum, then (a) (b) (c) (d)

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222

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Acirclewithcenter passes through theorigin.Theequationof the tangent tothe circle at the origin is (b) (d)

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223

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Theareaofthetriangleformedbyjoiningtheorigintothepointofintersectionoftheline andthecircle is3(b)4(c)5(d)6

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224

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If isapointonthecirclewhosecenterisonthex-axisandwhichtouchestheline at then the greatest value of is (a) (b) 6 (c)

(d)

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225

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Aregion in the plane isboundedby thecurve and the line.Ifthepoint liesintheinterioroftheregion,then (b)

(d)noneofthese

A(1, 0)andB(5, 0),C(0, h). ∠ACB h = 3√5 h = 2√5 h = √5h = 2√10

(a, b)ax − by = 0 ax + by = 0 bx − ay = 0

bx + ay = 0

x√5 + 2y = 3√5 x2 + y ∘ = 10

(α, β)x + y = 0 (2, − 2), α 4 − √2

4 + 2√2 +√2

x− y y = √25 − x2

y = 0 (a, a + 1) a ∈ ( − 4, 3)a ∈ ( −∞, − 1) ∈ (3, ∞) a ∈ ( − 1, 3)

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226

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Therearetwocircleswhoseequationare and

If the two circles have exactly two common tangents, then the number of possiblevaluesof is2(b)8(c)9(d)noneofthese

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227

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

isacircleofradius1touchingthex-andthey-axis. isanothercircleofradiusgreaterthan1andtouchingtheaxesaswellasthecircle .Thentheradiusofis (b) (d)noneofthese

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228

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

The equation of the incircle of equilateral triangle where and lies in the fourth quadrant is

noneofthese

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

x2 + y2 = 9x2 + y2 − 8x − 6y + n2 = 0, n ∈ Z.

n

C1 C2C1 C2

3 − 2√2 3 + 2√2 3 + 2√3

ABCB ≡ (2, 0),C ≡ (4, 0), A

x2 + y2 − 6x + + 9 = 02y

√3x2 + y2 − 6x − + 9 = 0

2y

√3

x2 + y2 + 6x + + 9 = 02y

√3

f(x, y) = x2 + y2 + 2ax + 2by + c= 0

( , 0) = 0 2, (0, ) = 0

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229representsacircle.If hasequalroots,eachbeing and

has 2 and 3 as its roots, then the center of the circle is (b)Data are not

sufficient (d)Dataareinconsistent

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230

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Theareaboundedbythecircles andthepairof lines

isequalto (b) (c) (d)

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231

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

The straight line will touch the circle if(b) (d)noneofthese

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232

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Let be a quadrilateral with are , side parallel to the side . Let be perpendicular to . If a circle is

drawninsidethequadrilateral touchingallthesides,thenitsradiusis (b)2

(c) (d)1

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233

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Consider a family of circleswhich are passing through the point and aretangenttothex-axis.If arethecoordinatesofthecenterofthecircles,thenthe

setofvaluesof isgivenbytheinterval. (b) (d)`0

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f(x, 0) = 0 2, f(0, y) = 0

(2, )52

( − 2, − )52

x2 + y2 = 1, x2 + y2 = 4,

√3(x2 + y2) = 4xyπ

25π2

3ππ

4

x cos θ + y sin θ = 2 x2 + y2 − 2x = 0θ = nπ, n ∈ IQ A = (2n + 1)π, n ∈ I θ = 2nπ, n ∈ I

ABCD 18 ABCD, andAB = 2CD AD ABandCD

ABCD 332

( − 1, 1)(h, k)

k k ≥12

− ≤ k ≤12

12k ≤

12

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234

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Iftheconicswhoseequationsare

intersect at four concyclic points, then, (where (b) (d)noneofthese

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235

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Therangeofvaluesof suchthattheangle betweenthepairof tangents

drawnfrom tothecircle liesin is(a)

(b) (c) (d)noneofthese

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236

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Thecirclewhichcanbedrawntopassthrough(1,0)and(3,0)andtotouchthey-axis

intersectatangle Then isequalto (b) (c) (d)

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237

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Thelocusofthemidpointsofthechordsofcontactof fromthepointsontheline isacirclewithcenter If istheorigin,then isequalto

2(b)3(c) (d)

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S ≡ sin2 θx2 + 2hxy + cos2 θy2

+ 32x + 16y + 19 = 0, S ′

≡ cos2 θx2 + 2h ′xy + s ∈2 θy2

+ 16x + 32y + 19 = 0θ ∈ R) h + h ′ = 0 h = h'

h + h ′ = 1

λ, λ > 0 θ

(λ, 0) x2 + y2 = 4 ( , )π

22π3

( , )4

√3

2

√2(0, √2) (1, 2)

θ. cos θ12

−12

14

−14

x2 + y2 = 23x + 4y = 10 P . O OP

12

13

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238

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Suppose , where are in be normal to a family ofcircles. The equation of the circle of the family intersecting the circle

orthogonally is (a) (b) (c) (d)

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239

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Ifacircleofradius istouchingthelines inthefirstquadrantat

points ,thentheareaoftriangle beingtheorigin)is(a) (b)

(c) (d)

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240

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Let be anymoving point on the circle be the chord ofcontact of this point w.r.t. the circle . The locus of thecircumcenter of triangle being the center of the circle) is

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ax+ by + c = 0 a, bandc AP

x2 + y2 − 4x − 4y − 1 = 0 x2 + y2 − 2x + 4y − 3 = 0x2 + y2 − 2x + 4y + 3 = 0 x2 + y2 + 2x + 4y + 3 = 0x2 + y2 + 2x − 4y + 3 = 0

r x2 − 4xy + y2 = 0

AandB OAB(O 3√3r2

4√3r2

43r2

4r2

P x2 + y2 − 2x = 1. ABx2 + y2 − 2x = 0

CAB(C2x2 + 2y2 − 4x + 1 = 0 x2 + y2 − 4x + 2 = 0 x2 + y2 − 4x + 1 = 02x2 + 2y2 − 4x + 3 = 0

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241

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Twocirclesof radii touchingeachotherexternally,are inscribed in thearea

boundedby andthex-axis.If then isequalto (b) (c)

(d)

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242

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Fromanarbitrarypoint onthecircle ,tangentsaredrawntothecircle , which meet at . The locus of the point of

intersectionoftangentsat tothecircle is

(b) (d)noneofthese

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243

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If are the radii of the smallest and the largest circles, respectively, which

passthough(5,6)andtouchthecircle then is (b)

(d)

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244

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

The minimum radius of the circle which is orthogonal with both the circlesand is4(b)3(c) (d)1

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245

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If isacircleand and areapairoftangentsonwhere isanypointonthedirectorcircleof thentheradiusofthesmallest

circlewhichtouches externallyandalsothetwotangents and is(b) (d)1

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aandb

y = √1 − x2 b = ,12

a14

18

12

1

√2

P x2 + y2 = 9x2 + y2 = 1 x2 + y2 = 9 AandB

AandB x2 + y2 = 9 x2 + y2 = ( )2277

x2 − y2( )2277

y2 − x2 = ( )2277

r1andr2

(x − 2)2 + y2 = 4, r1r2441

414

541

416

x2 + y2 − 12x+ 35 = 0 x2 + y2 + 4x+ 3 = 0 √15

C1 : x2 + y2 = (3 + 2√2)2

PA PB

C1, P C1,c1 PA PB 2√3 − 3

2√2 − 1 2√2 − 1

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246

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Fromapoint ,twotangents aredrawntoagivencirclewhoseradiusis5.Ifthecircumcenteroftriangle is(2,3),thentheequationofthe circle is

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247

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

If the tangents are drawn from any point on the line to the circle,thenthechordofcontactpassesthroughthepoint.(3,5)(b)(3,3)(c)

(5,3)(d)noneofthese

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248

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

If the radius of the circumcircle of the triangle TPQ, where PQ is chord of contactcorresponding topointTwith respect to circle , is 6units,thenminimumdistancesofTfromthedirectorcircleofthegivencircleis

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249

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

isapoint in thefirstquadrant. If thetwocircleswhichpassthrough andtouch both the coordinates axes cut at right angles, then

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases Of

R(5, 8) RPandRQ S = 0PQR

S = 0 x2 + y2 + 2x + 4y − 20 = 0 x2 + y2 + x + 2y − 10 = 0x2 + y2 − x+ 2y − 20 = 0 x2 + y2 + 4x − 6y − 12 = 0

x + y = 3x2 + y2 = 9

x2 + y2 − 2x + 4y − 11 = 0

P (a, b) P

a2 − 6ab + b2 = 0a2 + 2ab − b2 = 0 a2 − 4ab + b2 = 0 a2 − 8ab + b2 = 0

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250

TwoCircles

Thenumberofcommontangent(s)tothecircles andis1(b)2(c)3(d)4

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251

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Two circles of radii 4cm and 1cm touch each other externally and is the angle

containedbytheirdirectcommontangents.Then isequalto (b) (d)

noneofthese

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252

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thelocusofthemidpointsofthechordsofthecircle which

subtend a right angle at is

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253

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Fromthepoints(3,4),chordsaredrawntothecircle .Thelocusof the midpoints of the chords is (a) (b)

(c) (d)

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

x2 + y2 + 2x + 8y − 23 = 0x2 + y2 − 4x − 10y − 19 = 0

θ

sin θ2425

1225

34

x2 + y2 − ax − by = 0

( , )a

2b

2ax + by = 0 ax + by = a2 = b2

x2 + y2 − ax − by + = 0a2 + b2

8x2 + y2 − ax− by − = 0

a2 + b2

8

x2 + y2 − 4x = 0x2 + y2 − 5x − 4y + 6 = 0

x2 + y2 + 5x − 4y + 6 = 0 x2 + y2 − 5x + 4y + 6 = 0x2 + y2 − 5x − 4y − 6 = 0

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254

Theanglesatwhichthecircles

intersectis (b) (c) (d)

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255

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Atangentatapointonthecircle intersectsaconcentriccircle attwopoints .Thetangentstothecircle at meetatapointonthecircle

Then the equation of the circle is

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256

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Tangent are drawn to the circle at the points where it is met by thecircles

being the variable. The locus of the point of intersection of these tangents is(b) (d)

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257

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

If points are (1, 0) and (0, 1), respectively, and point is on the circle , then the locusof theorthocentreof triangle is

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(x − 1)2 + y2 = 10andx2

+ (y − 2)2 = 5π

2

x2 + y2 = a2 CPandQ X PandQ

x2 + y2 = b2 . x2 + y2 = abx2 + y2 = (a − b)2 x2 + y2 = (a + b)2 x2 + y2 = a2 + b2

x2 + y2 = 1

x2 + y2 − (λ + 6)x + (8 − 2λ)y− 3 = 0, λ

2x− y + 10 = 0 2x + y − 10 = 0 x − 2y + 10 = 0 2x + y − 10 = 0

AandB Cx2 + y2 = 1 ABC x2 + y2 = 4x2 + y2 − x− y = 0 x2 + y2 − 2x − 2y + 1 = 0x2 + y2 + 2x − 2y + 1 = 0

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258

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the line is theequationofa transversecommon tangent tothecircles and ,thenthevalueof

is (b) (c) (d)

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259

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Any circle through the point of intersection of the lines and intersects these linesatpoints .Then theanglesubtended

bythearc atitscenteris (b) (c) dependsoncenterandradius

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260

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Iftheanglebetweenthetangentsdrawnto from(0,0)is then

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261

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Thecommonchordof thecircle andacirclepassingthrough the origin and touching the line always passes through the point.

(b)(1,1) (d)noneofthese

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262

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

The chords of contact of tangents from three points to the circleareconcurrent.Then will (a)beconcyclic (b)becollinear

(c)formtheverticesofatriangle(d)noneofthese

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263

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

The chord of contact of tangents from a point to a circle passes through Ifarethelengthofthetangentsfrom tothecircle,then isequalto

(b) (d)

x cos θ + y sin θ = 2x2 + y2 = 4 x2 + y2 − 6√3x − 6y + 20 = 0 θ

5π6

2π3

π

6

x +√3y = 1√3x − y = 2 PandQ

PQ 1800 900 1200

x2 + y2 + 2gx + 2fy + c = 0,

π

2g2 + f 2 = 3c g2 + f2 = 2c g 2 + f2 = 5c g2 + f 2 = 4c

x2 + y2 + 6x + 8y − 7 = 0y = x

( − , )12

12

( , )12

12

A, BandCx2 + y2 = a2 A, BandC

P Q.l1andl2 PandQ PQl1 + l2

2l1 − l2

2√l12 + l22 2√l12 + l22

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264

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Let are circles defined by and. The length of the shortest line segment PQ that is

tangentto atPandto atQis

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265

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Theendsofaquadrantofacirclehave thecoordinates (1,3)and (3,1).Then thecenterofsuchacircleis

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266

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

If the line is a normal to the circle and atangenttothecircle ,then

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267

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Theradiusofthetangentcirclethatcanbedrawntopassthroughthepoint(0,1)and(0,6)andtouchingthex-axisis(a)5/2(b)Â3/2(c)7/2(d)9/2

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C1 and C2 x2 + y2 − 20x + 64 = 0x2 + y2 + 30x+ 144 = 0

C1 C2

ax + by = 2 x2 + y2 − 4x− 4y = 0x2 + y2 = 1 a and bare

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268

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Theequationof the tangent to thecircle whichmakesa triangleofarea with the coordinate axes, is (b)

(d)

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269

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

If the circle is touched by at such thatthenthevalueof is36(b)144(c)72(d)noneofthese

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270

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The number of points lying inside or on the circle andsatisfyingtheequation is______

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271

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Theareaofthetriangleformedbythepositive axisandthenormalandtangentto the circle at is (a) (b) (c)

(d)noneofthese

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

x2 + y2 = a2,a2 x± y = a√2 x± y = ± a√2

x ± y = 2a x + y = ± 2a

x2 + y2 + 2gx + 2fy + c = 0 y = x POP = 6√2, c

P(x, y) x2 + y2 = 9tan4 x+ cot4 x + 2 = 4 sin2 y

x−x2 + y2 = 4 (1, √3) 2√3sq

.units 3√2sq

.units

√6sq.units

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272

Let beapointonthecircle apointontheline ,and the perpendicular bisector of be the line . Then the

coordinatesof are (b) (d)

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273

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Astraight linemoves such that thealgebraic sumof theperpendicularsdrawn to itfromtwofixedpointsisequalto .Then, thenstraight linealwaystouchesafixed

circleofradius. (b) (c) (d)noneofthese

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274

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thecoordinatesofthemiddlepointofthechordcut-offby bythecircle are (b) (c) (d)

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275

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

The locus of the point from which the lengths of the tangents to the circles and are equal is a straight line

inclinedat withthelinejoiningthecentersofthecirclesacircle(c)anellipse(d)a

straightlineperpendiculartothelinejoiningthecentersofthecircles.

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The equation of the circumcircle of an equilateral triangle is

P x2 + y2 = 9, Q 7x + y + 3 = 0PQ x − y + 1 = 0

P (0, − 3) (0, 3) ( , )7225

2135

( − , )7225

2125

2k

2kk

2k

2x − 5y + 18 = 0x2 + y2 − 6x + 2y − 54 = 0 (1, 4) (2, 4) (4, 1) (1, 1)

x2 + y2 = 4 2(x2 + y2) − 10x+ 3y − 2 = 0π

4

2 2

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276

and one vertex of the triangle in (1, 1). Theequationoftheincircleofthetriangleis

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277

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Tangents and aredrawnto fromanyarbitrarypoint ontheline . The locus of the midpoint of chord is

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278

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Thecircleshaving radii intersectorthogonally.The lengthof theircommonchordis`

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279

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

If thepairofstraight lines is tangent to thecircleat fromthe origin such that the area of the smaller sector formed by is

where isthecenterofthecircle,the equals (b) (c)

3(d)

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280

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

The two circles which pass through and touch the line will intersect each other at right angle if

(d)

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281

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Theconditionthatthechord of maysubtendarightangleatthecenterofthecircleis

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x2 + y2 + 2gx + 2fy + c = 04(x2 + y2) = g2 + f2

4(x2 + y2) = 8gx+ 8fy

= (1 − g)(1 + 3g)

+ (1 − f)(1 + 3f)4(x2 + y2) = 8gx+ 8fy = g2 + f2 noneofthese

PA PB x2 + y2 = 9 Px + y = 25 AB

25(x2 + y2) = 9(x + y) 25(x2 + y2) = 3(x+ y) 5(x2 + y2) = 3(x + y)noneofthese

r1andr2

xy√3 − x2 = 0 PandQO CPandCQ

3πsq.unit, C OP

(3√3)2

3√3

√3

(0, a)and(0, − a)y = mx + c a2 = c2(2m + 1)a2 = c2(2 +m2) c2 = a2(2 + m2) c2 = a2(2m + 1)

x cosα + y sinα − p = 0 x2 + y2 − a2 = 0

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282

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Thelocusofthemidpointofachordofthecircle whichsubtendsarightangleattheoriginsis (b) (d)

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283

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

Ifthechordofcontactoftangentsfromapoint toagivencirclepassesthroughthen the circle on as diameter. cuts the given circle orthogonally touches thegivencircleexternallytouchesthegivencircleinternallynoneofthese

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284

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Letthebase ofatriangle befixedandthevertex liesonafixedcircleofradius Linesthrough aredrawntointersect respectively,at

suchthat .Ifthepointofintersection of these lines lies on themedian through for all positions of then the

locusof isacircleofradius acircleofradius aparabolaoflatusrectum a

rectangularhyperbola

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285

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of TheChordBisectedAtAGivenPoints

Thenumberof intergralvalueof forwhich thechordof thecirclepassingthroughthepoint getsbisectedatthepoint andhasintegralslopeis8(b)6(c)4(d)2

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x2 + y2 = 4x + y = 2 x2 + y2 = 1 x2 + y2 = 2 x + y = 1

P Q,PQ

AB ABC Cr. AandB CBandCA,

EandF CE :EB = 1: 2andCF :FA = 1: 2P AB AB,

Pr

22r 4r

y x2 + y2 = 125P(8, y) P(8, y)

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286

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Considersquare ofsidelength1.Let bethesetofallsegmentsoflength1withendpointsontheadjacentsidesofsquare .Themidpointsofsegmentsin enclosearegionwitharea Thevalueof is(a) (b) (c) (d)

noneofthese

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287

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

The rangeofvaluesof forwhich the line isanormal to thecircle for all values of is (a) (b) (c)

(d)

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288

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

)Sixpoints(x,yi),i=1,2, ,.., 6are takenon thecirclex4such that thecirclex2+y4such that 6 6 J:1-8 and Σ, 4 . The line segment X,=8 and and 2-yi = 4. The linesegment x1 i=1 joining orthocentre of a triangle formed by any three points andcentroidofa triangle formedbyother threepointspasses througha fixed i=1points(h,k),thenh+kisA)1B)2C)3D)4

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289

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

A circle with radius and center on the y-axis slied along it and a variable linethrough (a, 0) cuts the circle at points . The region in which the point ofintersection of the tangents to the circle at points and lies is represented by

(b) (d)

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

ABCD PABCD

P A. Aπ

41 −

π

44 −

π

4

α 2y = gx + αx2 = y2 + 2gx + 2gy − 2 = 0 g [1,∞) [ − 1, ∞)(0, 1) ( − ∞, 1]

|a|PandQ

P Qy2 ≥ 4(ax − a2) y2 ≤ 4(ax − a2) y ≥ 4(ax − a2) y ≤ 4(ax − a2)

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290If the angle of intersection of the circle and

is ,thentheequationofthelinepassingthrough(1,2)andmaking an angle with the y-axis is (a) (b) (c) (d)

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291

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Thecentersofasetofcircles,eachofradius3,lieonthecircle .Thelocusofanypointinthesetis (d)

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292

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Thecoordinatesoftwopoints are istheorigin.Ifthe circles are described on as diameters, then the length of their

common chord is (b) (d)

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293

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Consideracircle lyingcompletelyinthefirstquadrant.

If arethemaximumandminimumvaluesof forallorderedpairs

onthecircumferenceof thecircle, thenthevalueof is(a) (b)

(c) (d)

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x2 + y2 + x + y = 0x2 + y2 + x− y = 0 θ

θ x = 1 y = 2 x+ y = 3x − y = 3

x2 + y2 = 254 ≤ x2 + y2 ≤ 64 x2 + y2 ≤ 25 x2 + y2 ≥ 25

3 ≤ x2 + y2 ≤ 9

PandQ (x1, y1)and(x2, y2)andOOPandOQ

|x1y2 + x2y1|PQ

|x1y2 − x2y1|PQ

|x1x2 + y1y2|PQ

|x1x2 − y1y2|PQ

x2 + y2 + ax + by + c = 0m1andm2

y

x(x, y)

(m1 + m2)a2 − 4c

b2 − 4c2abb2 − 4c

2ab4c − b2

2abb2 − 4ac

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294

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

The equation of the circle passing through the point of intersection of the circle and the line and havingminimumpossible radius is (a)

(b) (c)(c)

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295

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The locus of the center of the circle touching the line at is (a)(b) (c) (d)noneofthese

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296

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Thedistancefromthecenterofthecircle tothecommonchordofthecircles and is2(b)4

(c) (d)

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297

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

The equation of the circle passing through the point of intersection of the circles and and the point is

(a) (b) (c)(d)

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

x2 + y2 = 4 2x+ y = 15x2 + 5y2 + 18x+ 6y − 5 = 0 5x2 + 5y2 + 9x+ 8y − 15 = 05x2 + 5y2 + 4x + 9y − 5 = 0 5x2 + 5y2 − 4x − 2y − 18 = 0

2x− y = 1 (1, 1)x + 3y = 2 x + 2y = 2 x + y = 2

x2 + y2 = 2xx2 + y2 + 5x − 8y + 1 = 0 x2 + y2 − 3x + 7y − 25 = 0

3413

2617

x2 + y2 − 4x − 2y = 8 x2 + y2 − 2x − 4y = 8 ( − 1, 4)x2 + y2 + 4x + 4y − 8 = 0 x2 + y2 − 3x + 4y + 8 = 0

x2 + y2 + x+ y = 0 x2 + y2 − 3x − 3y − 8 = 0

2 2 2 2

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298 If the radiiof thecircle andareincreasinguniformlyw.r.t.timesas0.3unit/sisand0.4unit/s,thentheywilltoucheachotherat equalto (b) (c) (d)

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299

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The equation of the circlewhich has normals and a tangent is

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300

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Awheelofradius8unitsrollsalongthediameterofasemicircleofradius25units;itbumps into this semicircle. What is the length of the portion of the diameter thatcannotbetouchedbythewheel?12(b)15(c)17(d)20

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301

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Thepoint([p+1],[p])islyinginsidethecircle .Thenthesetofallvaluesof is(where[.]representsthegreatestintegerfunction)(a) (b)

(c) (d)

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302

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Thesquared lengthof the interceptmadeby the line on thepairof tangentsdrawn from the origin to the circle is

(x − 1)2 + (y − 2)2 = 1 (x − 7)2 + (y − 10)2 = 4

t 45s 90s 11s 135s

x − 1). (y − 2) = 03x+ 4y = 6 x2 + y2 − 2x − 4y + 4 = 0 x2 + y2 − 2x − 4y + 5 = 0x2 + y2 = 5 (x − 3)2 + (y − 4)2 = 5

x2 + y2 − 2x − 15 = 0p [ − 2, 3)

( − 2, 3) [ − 2, 0) ∪ (0, 3) [0, 3)

x = hx2 + y2 + 2gx + 2fy + c = 0

4 2 4 2 4 2

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(d)noneofthese

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303

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

TwoparalleltangentstoagivencirclearecutbyathirdtangentatthepointsIf isthecenterofthegivencircle,then dependsontheradiusofthecircle.depends on the center of the circle. depends on the slopes of three tangents. isalwaysconstant

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304

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Three equal circles each of radius touch one another. The radius of the circle

touching all the three given circles internally is (b)

(d)

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305

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

If the radius of the circumcircle of the triangle TPQ, where PQ is chord of contactcorresponding topointTwith respect to circle , is 6units,thenminimumdistancesofTfromthedirectorcircleofthegivencircleis

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(g2 + f2 − c)4ch2

(g2 − c)2(g2 + f2 − c)

4ch2

(f2 − c)2(g2 + f2 − c)

4ch2

(f 2 − f2)2

AandB.C ∠ACB

r

(2 + √3)r r(2 + √3)

√3

r(2 − √3)

√3(2 − √3)r

x2 + y2 − 2x + 4y − 11 = 0

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306

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

The equation of the locus of the middle point of a chord of the circle such that the pair of lines joining the origin to the point of

intersectionofthechordandthecircleareequallyinclinedtothex-axisis(b) (d)noneofthese

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307

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Theequationofcircleofminimumradiuswhichcontactsthethreecircle

thentheradiusofgivencircleis thenthevalueofl+mis:

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308

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

If the length of the common chord of two circles andis , thenthevaluesof are (b) (c) (d)

noneofthese

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309

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

A triangle is inscribed in a circle of radius1.Thedistancebetween theorthocentreandthecircumcentreofthetrianglecannotbe

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310

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Acircle ofradiusbtouchesthecircle externallyandhasitscentreon thepositiveX-axis;anothercircle of radiusc touches thecircle , externallyandhasitscentreonthepositivex-axis.Given thenthreecircleshaveacommontangentifa,b,carein

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x2 + y2 = 2(x + y)x + y = 2

x − y = 2 2x − y = 1

x2 + y2 − 4y − 5 = 0, x2 + y2

+ 12x + 4y + 31 = 0, x2 + y2

+ 6x + 12y + 36 = 0(l+ √949)m

36

x2 + y2 + 8x+ 1 = 0x2 + y2 + 2μy − 1 = 0 2√6 μ ±2 ±3 ±4

C1 x2 + y2 = a2

C2 C1a < b < c

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311

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Let , , be circles of radii 5,3,2 respectively. and , touch each otherexternallyandCinternally.Acircle touches and externallyandCinternally.Ifitsradiusis wheremandnarerelativelyprimepositiveintegers,then2n-mis:

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312

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the circle lies completely inside the circle then a) b) c)

d)

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313

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Considerthecircle .LetObethecentreofthecircleand tangent at A(7,3) and B(5, 1) meet at C. Let S=0 represents family of circlespassingthroughAandB,then

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314

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Tangent drawn from the point to the circle will beperpendiculartoeachotherif equals5(b) (c)4(d)

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

C C1 C2 C1 C2C3 C1 C2

m

n

x2 + y2 + 2a1x + c = 0x2 + y2 + 2a2x+ c = 0 a1a2 > 0, c < 0 a1a2 > 0, c > 0a1a2 < 0, c < 0 a1a2 < 0, c > 0

x2 + y2 − 10x − 6y + 30 = 0

(a, 3) 2x2 + 2y2 = 25a −4 −5

1 1

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315isapointonthecircle and isanotherpointon the

circle such that are length units. Then, the coordinates of can be

(b) (d)noneofthese

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316

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Let berealvariablessatisfying .Let

and . Then (b)

(d)

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317

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Threesidedofatrianglehaveequations Then where is the equation of the

circumcircleofthetriangleif

noneofthese

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

A( , )1

√2

1

√2x2 + y2 = 1 B

AB =π

2B

( , 1√2)1

√2( − , 1√2)1

√2( − , − )1

√2

1

√2

xandy x2 + y2 + 8x− 10y − 40 = 0a =

max {√(x + 2)2 + (y − 3)2}b = min {√(x + 2)2 + (y − 3)2} a + b = 18 a + b = √2

a − b = 4√2 a.b = 73

L1 ≡ y −mix = o; i = 1, 2and3.L1L2 + λL2L3 + μL3L1 = 0 λ ≠ 0, μ ≠ 0,

1 + λ + μ = m1m2 + λm2m3

+ λm3m1m1(1 + μ) +m2(1 + λ)

+ m3(μ + λ) = 0

+ + = 1 + λ + μ1m3

1m1

1m1

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318

Iftheequation

representsacircle,thentheconditionforthatcircletopassthroughthreequadrantsonlybutnotpassingthroughtheoriginis (b) (d)

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319

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

The points on the line from which the tangents drawn to the circleareatrightanglesis(are)(a) (b) (c)

(d)

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320

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Co-ordinatesof thecentreofacircle,whose radius is2unitandwhich touches thepairoflinesines is(are)

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321

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the circles and touch each

other,then is (b)0(c)1(d)

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322

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

PointMmovesonthecircle .Thenitbrokesawayfromitandmovingalonga tangent to thecircle,cuts thex-axisat thepoint (-2,0).Theco-ordinatesofapointonthecircleatwhichthemovingpointbrokeawayis

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323

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Theequationofthetangenttothecircle passingthrough is(b) (d)

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x2 + y2 + 2hxy + 2gx + 2fy + c= 0

f 2 > c g 2 > 2 c > 0 h = 0

x = 2x2 + y2 = 16 (2, 2√7) (2, 2√5) (2, − 2√7)

(2, − 2√5)

x2 − y2 − 2x + 1 = 0

x2 + y2 − 9 = 0 x2 + y2 + 2ax + 2y + 1 = 0

α −43

43

(x − 4)2 + (y − 8)2 = 20

x2 + y2 = 25 ( − 2, 11)4x+ 3y = 25 3x + 4y = 38 24x − 7y + 125 = 0 7x + 24y = 250

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324

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If the area of the quadrilateral by the tangents from the origin to the circleandtheradiicorrespondingtothepointsofcontactis

thenavalueof is9(b)4(c)5(d)25

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325

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

The equation of the circle which touches the axes of coordinates and the line and whose center lies in the first quadrant is

,where is(a)1(b)2(c)3(d)6

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326

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Theequationsoftangentstothecircle drawnfromtheoriginin (b) (c) (d)

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327

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Ifacirclepasses through thepointof intersectionof the lines andwiththecoordinateaxis,thenvalueof is

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

26Which of the following lines have the intercepts of equal lengths on the circle, (A) (B) (C)

x2 + y2 + 6x − 10y + c = 015, c

+ = 1x

3y

4x2 + y2 − 2cx − 2cy + c2 = 0 c

x2 + y2 − 6x− 6y + 9 = 0x = 0 x = y y = 0 x + y = 0

x+ y + 1 = 0x + λy − 3 = 0 λ

x2 + y2 − 2x + 4y = 0 3x − y = 0 x + 3y = 0 x + 3y + 10 = 03 − − 10 = 0

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328 (D)

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329

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The equation of the line(s) parallel to which touch(es) the circle is (are) (a) (b)

(c) (d)3

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330

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Thecircles and touchinternally touch externally have as the common tangent at thepoint of contact have as the common tangent at the point ofcontact

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331

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

The circles and a)aresuchthatthenumberofcommontangentsonthemis2b)areorthogonalc)are

suchthatthelengthoftheircommontangentsis d)aresuchthatthelength

oftheircommonchordis

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

3x − y − 10 = 0

x − 2y = 1x2 + y2 − 4x − 2y − 15 = 0 x − 2y + 2 = 0 x − 2y − 10 = 0x − 2y − 5 = 0 x − y − 10 = 0

x2 + y2 − 2x − 4y + 1 = 0 x2 + y2 + 4x + 4y − 1 = 03x + 4y − 1 = 0

3x + 4y + 1 = 0

x2 + y2 + 2x + 4y − 20 = 0 x2 + y2 + 6x − 8y + 10 = 0

5( )125

14

5√32

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332A particle from the point moves on the circle and aftercoveringaquarterofthecircleleavesittangentially.Theequationofalinealongwiththepointmovesafterleavingthecircleis

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333

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The equation of a circle of radius 1 touching the circles is

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334

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the circles and touch each

other,then is (b)0(c)1(d)

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335

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

The rangeofvaluesof such that theangle between thepairof tangentsdrawnfrom tothecircle satisfies`pi/2WatchFreeVideoSolutiononDoubtnut

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Iftheconicswhoseequationsare

P(√3, 1) x2 + y2 = 4

x2 + y2 − 2|x| = 0x2 + y2 + 2√2x + 1 = 0 x2 + y2 − 2√3y + 2 = 0x2 + y2 + 2√3y + 2 = 0 x2 + y2 − 2√2 + 1 = 0

x2 + y2 − 9 = 0 x2 + y2 + 2ax + 2y + 1 = 0

α −43

43

a θ(a, 0) x2 + y2 = 1

S1 : (sin2 θ)x2 + (2h tanθ)xy

+ (cos2 θ)y2 + 32x+ 16y + 19

= 0

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336

intersectatfourconcyclicpoints,where thenthecorrectstatement(s)can

be (b) (d)noneofthese

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337

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thecenter(s)ofthecircle(s)passingthroughthepoints(0,0)and(1,0)andtouching

the circle is (are) (a) (b) (c) (d)

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338

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Eachquestionhasfourchoicesa,b,candd,outofwhichonlyoneiscorrect.Eachquestion contains STATEMENT 1 and STATEMENT 2. Both the statements areTRUE and STATEMENT 2 is the correct explanation of STATEMENT1. Both thestatements are TRUE but STATEMENT 2 is NOT the correct explanation ofSTATEMENT 1. STATEMENT 1 is TRUE and STATEMENT 2 is FALSE.STATEMENT 1 is FALSE and STATEMENT 2 is TRUE. Statement 1:

, where is order of matrix Statement 2:

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339

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Statement1:Ifthechordsofcontactoftangentsfromthreepoints tothecircle areconcurrent,then willbecollinear.Statement2:Lines

alwasypassthroughafixedpointfor .

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340

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Statement1:Circles and donothaveanycommon tangent. Statement 2 : If two circles are concentric, then they do not havcommontangents.

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S1 : (sin2 θ)x2 − (2h ′ cot θ)xy

+ (sin2 θ)y2 + 16x+ 32y + 19

= 0θ[0, ],π

2h + h ′ = 0 h − h ′ = 0 θ =

π

4

x2 + y2 = 9 ( , )32

12

( , )12

32

( , 2 )12

12

( , − 2 )12

12

|adj(adj(adjA))| − |A|n−1 ^ 3 n A.|adjA| = |A|n.

A,BandCx2 + y2 = a2 A,BandC

(a1x + b1y + c1) + k(a2x + b2y

+ c2) = 0k ∈ R

x2 + y2 = 144 x2 + y2 − 6x − 8y = 0

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341

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Statement1:Theleastandgreatestdistancesofthepoint fromthecircleare6unitsand15units,respectively.Statement2:

A point lies outside the circle ifwhere

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342

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Statement1 :Thenumberofcirclespassing through(1,2), (4,8)and(0,0) isone.Statement2:Everytrianglehasonecircumcircle

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343

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Let bethecirclewithcenter andradius1and bethecirclewithcenterandradius2.Statement1:Circles alwayshave

at least one common tangent for any value of Statement 2 : For the two circleswhere aretheirradiiforanyvalueof

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344

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Tangentsaredrawnfromtheorigintothecircle

Statement 1 : Angle between the tangents is Statement 2 : The given circle is

P(10, 7)x2 + y2 − 4x − 2y − 20 = 0

(x1, y1) S = x2 + y2 + 2gx + 2fy + c = 0S1 > 0,S1 = x12 + y12 + 2gx1 + 2fy1 +⋅

C1 O1(0, 0) C2

O2(t, t2 + 1), (t ∈ R), C1andC2

tO1O2 ≥ |r1 − r2|, r1andr2 t.

x2 + y2 − 2hx − 2hy + h2 = 0,(h ≥ 0)

π

2

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touchingthecoordinateaxes.

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345

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Consider two circles andStatement1:Boththecirclesintersecteachotherattwodistinctpoints.Statement2:Thesumofradiiofthetwocirclesisgreaterthanthedistancebetweentheircenters.

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346

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

From the point , tangents are drawn to the circleStatement1:Theareaofquadrilateral beingtheorigin)is4.

Statement2:Theareaofsquareis where isthelengthofside.

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347

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Normal To A CircleAtAGivenPoint

Statement 1 : The center of the circle having and as itsnormals is (1, 2) Statement 2 : The normals to the circle always pass through itscenter

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x2 + y2 − 4x− 6y − 8 = 0 x2 + y2 − 2x − 3 = 0

P(√2, √6) PAandPB

x2 + y2 = 4 OAPB(Oa2, a

x + y = 3 x − y = 1

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348

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Statement 1 : The circle having equation intersectsboththecoordinateaxes.Statement2:Thelengthsof interceptsmadebythe

circle having equation are and

,respectively.

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349

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Statement1:Thechordofcontactofthecircle w.r.t.thepoints(2,3),(3, 5), and (1, 1) are concurrent. Statement 2 : Points (1, 1), (2, 3), and (3, 5) arecollinear.

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350

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Statement1 :Theequation represents, fordifferentvaluesof asystemofcirclespassingthroughtwofixedpointslyingonthex-axis.Statement 2 : is a circle and is a straight line. Thenrepresentsthefamilyofcirclespassingthroughthepointsofintersectionofthecircleandthestraightline(where isanarbitraryparameter).

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351

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

StatementIThechordofcontactoftangentfromthreepointsA,BandCtothecircleareconcurrent,thenA,BandCwillbecollinear.StatementIIA,Band

Calwayslieonthenormaltothecircle .

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352

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Statement1:Points

areconcyclic.Statement2:Points forman isosceles trapeziumor

meetat Then

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353

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Common Chord OfTwoCircles

Statement 1 : The equations of the straight lines joining the origin to the points ofintersection of and is

. Statement 2 : is the common chord ofand

x2 + y2 − 2x + 6y + 5 = 0xandy

x2 + y2 + 2gx + 2fy + c = 0 2√g2 − c2√f2 − c

x2 + y2 = 1

x2 + y2 − 2x − 2ay − 8 = 0a,

S = 0 L = 0 S + λL = 0

λ

x2 + y2 = a2

x2 + y2 = a2

A(1, 0), B(2, 3), C(5, 3),

andD(6, 0)A,B,C, andD

ABandCD E . EA.EB = EC

.ED.

x2 + y2 − 4x − 2y = 4 x2 + y2 − 2x − 4y − 4 = 0x − y = 0 y + x = 0x2 + y2 − 4x − 2y = 4 x2 + y2 − 2x − 4y − 4 = 0

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354

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

Statement 1 : Two orthogonal circles intersect to generate a common chord whichsubtendscomplimentaryanglesattheircircumferences.Statement2:Twoorthogonalcircles intersect togenerateacommonchordwhichsubtendssupplementaryanglesattheircenters.

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355

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

Statement-1: The point does not lie outside the parabola

when Statement-2: The point

liesoutsidetheparabola if .

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356

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Statement 1 : If the circle with center cut the circlesand , then both the intersections are

orthogonal.Statement2:Thelengthoftangentfrom for isthesameforboththegivencircles.

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Statement 1 : Let and

(sin α, cos aα)

y2 + x− 2 = 0 α ∈ [ , (5 ] ∪ [π, ]π

63π2

(x1, y1) y2 = 4ax y21 − 4ax1, 0

P(t, 4 − 2t), t ∈ R,x2 + y2 = 16 x2 + y2 − 2x − y − 12 = 0

P t ∈ R

S1 : x2 + y2 − 10x − 12y − 39 = 0,S2x

2 + y2 − 2x − 4y + 1 = 0

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357

Theradicalcenterofthesecirclestakenpairwiseis Statement2 :Thepointofintersectionofthreeradicalaxesofthreecirclestakeninpairsisknownastheradicalcenter.

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358

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Statement1:Theequationofchordthroughthepoint whichisfarthestfromthe center of the circle is .Statement1:Innotations,theequationofsuchchordofthecircle bisectedat

mustbe

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359

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Statement 1 : If two circles and touch each other, then Statement 2 :

Twocirclestouchotherifthelinejoiningtheircentersisperpendiculartoallpossiblecommontangents.

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360

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Statement 1 :The circles and

touch if Statement2 :Twocenters and radii

respectively,toucheachotherif

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

S3 : 2x2 + 2y2 − 20x = 24y + 78= 0.

( − 2, − 3).

( − 2, 4)x2 + y2 − 6x + 10y − 9 = 0 x + y − 2 = 0

S = 0(x1, y1) T = S.

x2 + y2 + 2gx + 2fy = 0x2 + y2 + 2g ′ x+ 2f ′ y = 0 f ′ g = fg ′ .

x2 + y2 + 2px + r = 0 x2 + y2 + 2qy + r = 0

+ = .1p2

1q2

1e

C1andC2 r1andr2,

|r1 ± r2| = c1c2.

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361Let and be two circles whose equations are and

and isavariablepoint

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362

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Let the lines and intersect at rightangles at (where are parameters). If the locus of is

,thenthevalueof is__________

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363

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Consider the family of circles passing through twofixedpoints .Thenthedistancebetweenthepoints is_____

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364

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

If realnumbers satisfy then theminimum

valueof is_________

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365

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Theline intersectsthecurve atpoints .Thecircle on as diameter passes through the origin. Then the value ofis__________

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C1 C2 x2 + y2 − 2x = 0x2 + y2 + 2x = 0 P(λ, λ)

(y − 2) = m1(x − 5) (y + 4) = m2(x − 3)P m1andm2 P

x2 + y2gx + fy + 7 = 0 |f + g|

x2 + y2 − 2x − 2λy − 8 = 0AandB AandB

xandy (x + 5)2 + (y − 12)2 = (14)2,

√x2 + y2

3x + 6y = k 2x2 + 3y2 = 1 AandBAB k2

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366

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

The sum of the slopes of the lines tangent to both the circles andis________

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367

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Director Circle AndItsEquation

Acircle isthedirectorcircleofthecircleisthedirectorcircleofcircle andsoon.Ifthesumofradiiofallthesecirclesis2,thenthevalueof is ,wherethevalueof is___________

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368

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Two circle are externally tangent. Lines and are common tangentswith on the smaller circle and the on the larger circle. If

thenthesquareoftheradiusofthecircleis___________

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369

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the lengthofacommoninternal tangent to twocircles is7,andthatofacommonexternaltangentis11,thentheproductoftheradiiofthetwocirclesis

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370

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Line segments and are diameters of the circle of radius one. If,thelengthoflinesegment is_________

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371

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Asshown in the figure, threecircleswhichhave thesame radius r,havecentresat. If theyhaveacommon tangentline,asshown then, their

radius'r'is-

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x2 + y2 = 1(x − 6)2 + y2 = 4

x2 + y2 + 4x − 2√2y + c = 0 S1andS1S2,

c k√2 k

PAB PA'B'AandA' B ′andB'

PA = AB = 4,

AC BD∠BDC = 600 AB

(0, 0); (1, 1) and (2, 1)

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372

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

The acute angle between the line and the circleis .Then

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373

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If two perpendicular tangents can be drawn from the origin to the circle,thenthevalueof is___

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374

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Let Numberofpoints oncircle suchthatareaoftrianglewhosevertiesareA,B,Cispositiveintegeris:

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375

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Ifthecircle

and toucheachother,thenthemaximumvalueofcis

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376

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Twocircles bothpass through thepoints and touchtheline at respectively.Thepossiblecoordinatesofapoint

suchthatthequadrilateral isaparallelogram,are Thenthevalueof is_________

3x − 4y = 5x2 + y2 − 4x + 2y − 4 = 0 θ 9 cosθ =

x2 − 6x+ y2 − 2py + 17 = 0 |p|

A( − 4, 0),B(4, 0) c = (x, y) x2 + y2 = 16

x2 + y2 + (3 + sin β)x + 2cos αy= 0x2 + y2 + 2cos αx + 2cy = 0

C1andC2 A(1, 2)andE(2, 1)4x − 2y = 9 BandD,

C, ABCD (a, b).|ab|

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377

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Difference invaluesof theradiusofacirclewhosecenter isat theoriginandwhichtouchesthecircle is_____________

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378

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Find the equation of the circle whose radius is which touches the circleexternallyatthepoint

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379

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Findtheequationofacirclewhichpassesthroughthepoint andwhosecentreisthelimitofthepointofintersectionofethlines

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380

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

.LetAbe thecentreof thecircle Suppose that thetangentsat thepointsB(1,7)andD(4,-2)on thecirclemeetat thepointC.Find theareaofthequadrilateralABCD

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x2 + y2 − 6x − 8y + 21 = 0

5andx2 + y2 − 2x − 4y − 20 = 0 (5, 5).

(2, 0)

3x+ 5y = 1and(2 + c)x + 5c2y

= 1asc→1 .

x2 + y2 − 2x − 4y − 20 = 0

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381

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Findtheequationsofthecirclespassingthroughthepoint andtouchingthelines and

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382

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Throughafixedpoint(h,k)secantsaredrawntothecircle .Thenthelocusofthemid-pointsofthesecantsbythecircleis

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383

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

If theabscissaandordinatesof twopoints are the roots of the equationsand , respectively, then find theequation

ofthecirclewith asdiameter.

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384

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Lines and touchacircleC1ofdiameter6.IfthecentreofC1,liesinthefirstquadrantthentheequationofthecircleC2,whichisconcentricwithC1,andcutsinterceptsoflength8ontheselinesis

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385

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Letagiven line intersect theXandYaxesatPandQrespectively.Letanotherline perpendicularto cuttheXandY-axesatRandS,respectively.ShowthatthelocusofthepointofintersectionofthelinePSandQRisacirclepassingthroughtheorigin

( − 4, 3)x + y = 2 x− y = 2

x2 + y2 = r2

PandQx2 + 2ax− b2 = 0 x2 + 2px − q2 = 0

PQ

5x + 12y − 10 = 0 5x − 12y − 40 = 0

L1L2 L1

Page 87: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

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386

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thecircle isinscribedinatrianglewhichhastwoofitssides along the coordinate axes. The locus of the circumcenter of the triangle is

.Find

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387

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Let beagivencircle.FindthelocusofthefootoftheperpendiculardrawnfromtheoriginuponanychordofSwhichsubtendsarightangleattheorigin.

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388

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

If(m_i,1/m_i),i=1,2,3,4areconcyclicpointsthenthevalueof is

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389

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

A circle touches the line at point P such that , Circle contains(-10,2) in its interior& lengthof itschordon the line is .Determinetheequationofthecircle

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

x2 + y2 − 4x − 4y + 4 = 0

x + y − xy + k(x2 + y2) = 012 k.

S ≡ x2 + y2 + 2gx + 2fy + c =

m1m2m3m4

y = x OP = 4√2x + y = 0 6√2

Page 88: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions

390 Twocircles,eachofradius5units,toucheachotherat(1,2).Iftheequationoftheircommontangentsis ,findtheequationsofthecircles.

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391

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Letacirclebegivenby

.Find the condition on if two chords each bisected by the x-axis, can be

drawntothecirclefrom

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392

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Considera familyof circlespassing through thepoints (3, 7) and (6,5).Answer thefollowingquestions.Numberofcircleswhichbelongtothefamilyandalsotouchingx-axisare

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393

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Find thecoordinatesof thepointatwhich thecirclesand touch each other. Also, find equations ofcommontangentstouchingthecirclesthedistinctpoints.

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394

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Findtheintervalsofthevaluesof forwhichtheline bisectstwochords

drawnfromthepoint tothecircle

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395

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Consider a curve and a point P not on the curve. A linedrawnfromthepointPintersectthecurveatpointsQandR.Ifheproduct isindeopendentoftheslopeofthelinethenshowthatthecurveisacircle

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4x + 3y = 10

2x(x − a) + y(2y − b) = 0,

(a ≠ 0, b ≠ 0)a and b

(a, )b2

x2 − y2 − 4x − 2y + 4 = 0x2 + y2 − 12x − 8y + 36 = 0

a y + x = 0

( , )1 + √2a2

1 − √2a2

2x2 + 2y2 − (1 + √2a)x

− (1 − √2a) = 0

ax2 + 2hxy + by2 = 1PQ. PR

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396

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Let beanycirclewithcentre Provethatatmosttworationalpointscanbethere on (A rational point is a point both of whose coordinates are rationalnumbers)

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397

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

C1andC2aretwoconcentriccircles,theradiusofC2beingtwicethatofC1.FromapointPonC2,tangentsPAandPBaredrawntoC1.ThenthecentroidofthetrianglePAB(a)liesonC1(b)liesoutsideC1(c) liesinsideC1(d)maylieinsideoroutsideC1butneveronC1

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398

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Let andbe two tangentsdrawn from(-2,0)onto thecircle .DeterminethecirclestouchingCandhaving astheirpairoftangents.Further,findtheequationsofallpossiblecommontangentstothesecircleswhentakentwoatatime

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399

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Let betheequationofpairoftangentsdrawnfromtheorigintoacircleofradius3,withcenter inthefirstquadrant. IfA isthepointofcontact.FindOA

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C (0, √2).C .

T1, T2 C :x2 + y2 = 1T1, T2

2x2 + y2 − 3xy = 0

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400

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Tangents are drawn from external poinl P(6,8) to the, circle find theradius rof thecirclesuch thatareaof triangle formedby the tangentsandchordofcontactismaximumis

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401

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

The radiusof theof circle touching the line at (1,-1) and cuttingorthogonallythecirclehavinglinesegmentjoining(0,3)and(-2,-1)asdiameteris

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402

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Two circles intersect at two distinct points in a line passingthrough meetscircles at ,respectively.Let bethemidpointof

meetscircles at , respectively.Thenprovethatisthemidpointof

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403

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thetwopoints and inaplanearesuchthatforallpoints liesoncirclesatisfied

,then willnotbeequalto

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404

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

The points of intersection of the line and the circleare________and________

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x2 + y2 = r2

2x + 3y + 1 = 0

C1andC2 PandQP C1andC2 AandB Y

AB, andQY C1andC2 XandZ YXZ .

A B P

P B = kA

Pk

4x − 3y − 10 = 0x2 + y2 − 2x + 4y − 20 = 0

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405

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

If the lines and are tangents toacircle, thenfindtheradiusofthecircle.

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406

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

findtheareaof thequadrilateral formedbyapairof tangents fromthepoint(4,5) tothecircle andpairofitsradii.

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407

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Fromtheorigin,chordsaredrawntothecircle .Theequationofthelocusofthemid-pointsofthesechordsiscirclewithradius

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408

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Theequationofthelinepassingthroughthepointsofintersectionofthecircles

is

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CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

3x − 4y + 4 = 0 6x − 8y − 7 = 0

x2 + y2 − 4x− 2y − 11 = 0

(x − 1)2 + y2 = 1

3x2 + 3y2 − 2x + 12y − 9

= 0 and x2 + y2 + 6x + 2y − 15= 0

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409

FromthepointA(0,3)onthecircle achordABisdrawn&extended to a M point such that AM=2AB. The equation of the locus of M is: (A)

(B) (C) (D)

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410

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Findtheareaofthetriangleformedbythetangentsfromthepoint(4,3)tothecircleandthelinejoiningtheirpointsofcontact.

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411

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

If the circle intersects another circle of radius in such a

manner that,thecommonchord isofmaximum lengthandhasaslopeequal to ,

thentheco-ordinatesofthecentreof are:

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412

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Theareaofthetriangleformedbythepositivex-axiswiththenormalandthetangenttothecircle at is

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413

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

If a circle passes through the points of intersection of the coordinate axeswith thelines and ,thenthevalueof is............

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x2 + 4x+ (y − 3)2 = 0

x2 + 8x+ y2 = 0 x2 + 8x + (y − 3)2 = 0 (x − 3)2 + 8x + y2 = 0x2 + 8x+ 8y= 0

x2 + y2 = 9

C1 :x2 + y2 = 16 C2 534

C2

x2 + y2 = 4 (1, √3)

λx − y + 1 = 0 x − 2y + 3 = 0 λ

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414

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

The equation of the locus of the mid-points of chords of the circlethatsubtendsanangleofatitscentreis atits

centreis thenkis

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415

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Intersection Of ALineAndACircle

Theinterceptontheline bythecircle isAB.EquationofthecirclewithABasadiameteris

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416

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Twoverticesofanequilateraltriangleare and(1,0),anditsthirdvertexliesabovethex-axis.Theequationofitscircumcircelis____________

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417

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

The chords of contact of the pair of tangents drawn from each point on the linetothecircle passthroughthepoint(a,b)then4(a+b)is

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418

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Position Of PointsWithRespectToACircle

No tangentcanbedrawn from thepoint to thecircumcircleof the triangle

withvertices .

4x2 + 4y2 − 12x+ 4y + 1 = 0 2π

3x2 + y2 − kx + y + = 0

3116

y = x x2 + y2 − 2x = 0

( − 1, 0)

2x+ y = 4 x2 + y2 = 1

( , 1)52

(1, √3), (1, − √3), (3, − √3)

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419

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Theline isadiameterofthecircle

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420

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

A square is inscribed in the circle . Its sides areparallel to the coordinate axes. One vertex of the square is (b)

(d)noneofthese

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421

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_FamilyOfCircle

Twocircle and aregiven.Then theequationof the circle through their points of intersection and the point (1, 1) is

none ofthese

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422

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

Thelocusofthemidpointofachordofthecircle whichsubtendsarightangleattheoriginsis (b) (d)

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

If a circle passes through the point and cuts the circle

x + 3y = 0 x2 + y2 − 6x + 2y = 0

x2 + y2 − 2x + 4y + 3 = 0(1 + √2, − 2)

(1 − √2, − 2) (1, − 2 + √2)

x2 + y2 = 6 x2 + y2 − 6x+ 8 = 0

x2 + y2 − 6x + 4 = 0 x2 + y2 − 3x + 1 = 0 x2 + y2 − 4y + 2 = 0

x2 + y2 = 4x + y = 2 x2 + y2 = 1 x2 + y2 = 2 x + y = 1

(a, b) x2 + y2 = k2

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423 orthogonally,thentheequationofthelocusofitscenteris

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424

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

Ifthetwocircles

intersectintwodistinctpoint,then

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425

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Definition

Thelines and arethediametersofacircleofarea154sq. units. Then the equation of the circle is

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426

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

The centre of a circle passing through (0,0), (1,0) and touching the CircIe

isa. b. c. d.

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427

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

The locus of the centre of a circle which touches externally the circleandalsotouchesY-axis,isgivenbytheequation(a)

x2-6x-10y+14=0(b)x2-10x-6y+14=0(c)yr_6x-10y+14-0(d)y,2-10x-6y+14=0

(x − 1)2 + (y − 3)2 = r2 and x2

+ y2 − 8x + 2y + 8 = 0

2x − 3y = 5 3x − 4y = 7x2 + y2 + 2x − 2y = 62

x2 + y2 + 2x − 2y = 47 x2 + y2 − 2x + 2y = 47 x2 + y2 − 2x + 2y = 62

x2 + y2 = 9 ( , √2)12

( , )12

3

√2( , )32

1

√2( , − )12

1

√2

x2 + y2 − 6x − 6y + 14 = 0

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428

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Problems Based OnLocus

Theanglebetweenthepairoftangentsdrawnfromapoint tothecircle

is .thentheequationofthelocusofthepoint is

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429

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

If twodistinctchords,drawn from thepoint (p,q)on thecircle(where arebisectedbythex-axis,then (b) (d)

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430

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_RadicalAxis

An acute triangle PQR is inscribed in the circle . If Q and R havecoordinates(3,4)and(-4,3)respectively,thenfind .

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431

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_OrthogonalIntersectionOfCircles

Ifthecircles

intersectorthogonallythenkequals

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Px2 + y2 + 4x − 6y + 9 sin2 α

+ 13 cos2 α = 0

2α P x2 + y2 + 4x − 6y + 4 = 0x2 + y2 + 4x − 6y − 9 = 0 x2 + y2 + 4x − 6y − 4 = 0x2 + y2 + 4x − 6y + 9 = 0

x2 + y2 = px + qypq ≠ q) p2 = q2 p2 = 8q2 p2 < 8q2

p2 > 8q2

x2 + y2 = 25∠QPR

x2 + y2 + 2x + 2ky + 6

= 0 and x2 + y2 + 2ky + k = 0

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432

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Let beachordofthecircle subtendingarightangleatthecenter.Then the locus of the centroid of the as moves on the circle is (1) Aparabola(2)Acircle(3)Anellipse(4)Apairofstraightlines

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433

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Let betangentattheextremitiesofthediameter ofacircleofradiusIf intersectatapoint onthecircumferenceofthecircle,thenprove

that .

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434

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

If the tangentat thepointon thecircle meets thestraightine atapointQonthey-axisthenthelengthofPQis

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435

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Thecentreofcircleinscribedinasquareformedbylines

is

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CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Different Cases OfTwoCircles

AB x2 + y2 = r2

ΔPAB P

PQandRS PRr. PSandRQ X

2r = √PQxRS

x2 + y2 + 6x + 6y = 25x − 2y + 6 = 0

x2 − 8x+ 12 = 0andy2 − 14y + 45= 0(4, 7) (7, 4) (9, 4) (4, 9)

2 2

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436 Ifoneof thediametersof thecircle isachord to thecirclewithcentre(2,1),thentheradiusofcircleis:1. (2) (3)3(4)2

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437

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

A circle is given by , another circle C touches it externally andalsothex-axis,thenthelocusofcenteris:

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438

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of CircleWithTypicalConditions

Thecirclepassingthroughthepoint(-1,0)andtouchingthey-axisat(0,2)alsopassesthroughthepoint(A)(-3/2,0)(B)(-5/2,2)(C)(-3/2,5/2)(D)(-4,0)‘..22)

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439

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_ChordOfContact

Thelocusofthemid-pointofthechordofcontactoftangentsdrawnfrompointslyingonthestraightline tothecircle is:

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440

CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Tangent To A CircleAtAGivenPoint

Tangentsaredrawnfromthepoint(17,7)tothecircle ,Statement IThe tangentsaremutuallyperpendicularStatement, llsThe locusof thepoints frornwhich mutually perpendicular tangents can be drawn to the given circle is

(a)Statement I is correct,Statement II is correct;Statement II isacorrect explanation forStatementl (b(Statement I is correct, Statement I| is correctStatement II is not a correct explanation for Statementl (c)Statement I is correct,StatementIIisincorrect(d)StatementIisincorrect,StatementIIiscorrect

x2 + y2 − 2x − 6y + 6 = 0√3 √2

x2 + (y − 1)2 = 1

4x− 5y = 20 x2 + y2 = 9

x2 + y2 = 169

x2 + y2 = 338

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441

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

Consider: where isa realnumberand Statement1 : If line isachordofcircle thenline isnotalwaysadiameterofcircle Statement2:Iflineisaadiameterofcircle thenline isnotachordofcircle Boththestatementare True and Statement 2 is the correct explanation of Statement 1. Both thestatement are True but Statement 2 is not the correct explanation of Statement 1.Statement1isTrueandStatement2isFalse.Statement1isFalseandStatement2isTrue.

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442

CENGAGE_MATHS_COORDINATEGEOMETRY_CIRCLES_Miscellaneous

The straight line 2x − 3y = 1 divides the circular region into twoparts.IfS={

},thenthenumberofpoint(s)inSlyinginsidethesmallerpartis

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L1 : 2x + 3y + p − 3 = 0 L2 : 2x + 3y + p + 3 = 0 pC : x2 + y2 + 6x − 10y + 30 = 0 L1

C, L2 C. L1C, L2 C.

x2 + y2≠¤6

(2, ), ( , ), ( , − ),

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14

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Page 100: CENGAGE / G TEWANI MATHS SOLUTIONS CHAPTER CIRCLES || COORDINATE GEOMETRY … · 2018. 12. 8. · CENGAGE_MATHS_COORDINATE GEOMETRY_CIRCLES_Equation Of Circle With Typical Conditions