advanced level trigonometry tutorial
DESCRIPTION
A tutorial on Advanced level Trigonometry focusing on finding solutions and sketching graphsTRANSCRIPT
Sketch y : sin3x for 0 < r < 360'.
One cycle. We have 'compressed'3 cycles ofthe curve into the range 0-360o.
L Draw a sketch graph of the following for 0 < x < 360'.
a y: cos(r - 90o)
d y:3sinxb y:sinx-12 c y: tan(r*90")e y: cos2x
2 Match each equation with one of the sketch graphs below.
B: Y:cos(x-90') C:A, y: sin2xD, y: sin.x * 1 E: y:cosx-1
3 Draw a sketch graph of the following for 0 < r < 360".
F:
y: sin(x - 90")
y :2sinx
a y :2sinxdy=sin(x*90')
b y: tan2xe Y:2sinx*2
.tc y: smztr
L198
IIi
Draw a sketch graph of y : 2 sin(l + 180") for 0 < r < 360o.
Use your graph to write down the solution to the equation
2sin(r * 180.):2 (for0<r<360')
Draw a sketch graph of y : tanlxfor 0 < r < 350o.
How many solutions are there to the equation
tanlx : lz (for 0 < I < 360")
5* Draw a sketch graPh of the following for 0 < r < 360o.
4ab
5ab
7a
b
a Y: -costrd y: sin(-2r)
by:cos(-x) c y:1-cosxe Y: -2 sinx
On the same axes, sketch the curves y : cos4x and y : sin 2x f.or
0<x<90o.How many solutions are there to the equation cos 4x : sin 2r in this range?
8 a Sketchthecurve A :2tanZxfior0 (x{ z.
b In the range 0 < x < z how many solutions are there to the equation2tan2x:11?
1 Calculate the length of the side marked with a letter' All lengths are in cm.
In triangle ABC, a : 4.3, b : 7.2, c : 9. Find C.
nnIn triangle DEF, D : 58o, EF :7.2, DE = 5.4. Find F.
In triangle PQR, p : 8, 4 : 14, r: 7. Find 0.
199
6a
i In triangleh{Z,Y : 97.3",X2: 22, XY : 14. Find Z'
A point T is 11 km due north of a point S. A point_R,-which is east of the line
;oining T and S, is 8 km from T and 7 km from S. Calculate the bearing of R
from S.
A fourth point Q is on a bearing of 320" from s and is 10 km from T.
Calculate angle TQS and hence the bearing of T from Q'
7 Find the area of each triangle' All lengths are in cm'
8 An equilateral triangle has an area of 300 cm2. Calculate the length of the sidesof the triangle.
9 If sin 27" :0.454, give another angle whose sine is 0.454.
t1
Sort the following into pairs of equal value.
f-'i" 3o"l fcos 45"-l ltanrzs.l
li*55.] E,3oFlI tan 45" I l-ri" 45"-l icos6|
10
using surds where necessary.c sin 120.
f cos 30o
12 solve the fo'owing trigonometric equations in the given intervals(to 1 decimal place whEr".,"."rrrry ),asinx:-afor0<r<350o bcosr:_3. ^3 ., pcosr:_itor0<x<360.
c tanx:-0.7for0<x<360. dsinr:_lfor0<x<360o7-
the exact value of the following,b cos.45
e tan 135o
Write downa tan 60o
d cos 120o
For each diagram find:a the length of minor arc ABb the area of the minor sector AOB
Find all values of gbetween 0o and 360'for which
2sin0+8cos20:5,
giving your answers correct to the nearest 0.1o where necessary.
Sketch the following curves for 0 < x < 360"
solve the following trigonometric equations in the given intervals:
" ,ir,(*-:) : -€ 4, 0 -x12n b sin/x-'\ :1fo. 0lx'-2rr\ 2) z """'\^ 3) 2-"'"
. "o,("
. f) : -| rc,0,-x .-2n d tan(x - I):t for -z ( x I rr
a y:3sinrd y:1 * cosr
b y: cos(r - 90')e y :2cos4x
-l
16
1.8
c y: sinZx
Solve the following trigonometric equations in the given intervals:a cos2r * 2sin x - 2:0 for0'<.r<360'(1 exactvalue)b 2sin2 x - cos x - 1.:0 for 0 <.r < 2n (3 exactvalues)c 6cos2r * sin x - 5 :0 for -180o ( ff < 180" (2 exactvalues and 2 values
to 1 decimal place)
d 6sin2x * cos x - 4:0 for -180o (.tr< 180'(2 exactvalues and 2 valuesto 1 decimal place)
e 4cos2 x - 4sinx - 5 - 0 for -zr< x4 rr (2 exact values).
Find the exact solutions to the following trigonometric equations in the givenintervals:
a sin'(x* 3) :1 ro, -rr< x 1r\ 6) 2
b cosr(x- t\ :1 ro, o1x12n\ 3J +
c sin(x+a\:1 ro, o4x,-2,-\ 21 4
201
In triangle X:tz,} : 97'3",X2 : 22'XY : 14' Flr:'.dz'
aApointTis1LkmduenorthofapointS'ApointR'.*T"hiseastofthelinejoining T and s, Js k^ from T u"a /m trom s. Calculate the bearing of R
from S.
b A fourth point Q is on a bearing of 320" from S and is 10 km from T'
Calculate angle f-QS a"d hencJthe bearing of T from Q'
Find
a
the area of each triangle' All lengths are in cm'
Ft" 3o;l
tr" 45;l
|.*45"-l
Fi" 45f
It-'tFlt*'3oFl
F t 60;-l
11 Write downa tan 60"
d cos 120'b cos45
e tan 135o
c sin 120"
f cos 30o
the exact value of the following, using surds where necessary.
L2 solve the following trigonometric equations in the given intervals(to 1 decimal place where,","."rruryi e
ta sin *: -lforo<x<360o-J
c tan x: -0.7 for 0 < x < 360o
b cos *: -?for0<r<360o4
d sin r:-lforo<x{360o2
19 Solve the following trigonometric equations in the given intervals
a sin2(r - 40') :9 for 0o < x < 360" (exact values)4
1
b cos 2x : I for 0 < x 12rr (exact values)2
c 8cos2 x *2sinx-5:0 for0'<tr<360" (to L decimalplace)d sinr : 3 cos r for 0 <.r < 2n (to2 decimal places)
e 2sin2l : sin.r costr for 0 < r < 360o
20 In the diagram shown,r : radius of circlel: arc length0: angle at centre in radiansA : area of sector
a If r : 8cm and 0 : l.S,find l.b If r: 6 cm and 0 : 0.8, find A.c If I : 12crr. and 0 :1,, find r.d If A : 20 cm2 and r :2crr., find 9.
e If / : 50cm and r : 20cm, find 0.
f If A : 3cm2 and I : 3cm, find r and 0.
g If A : 8 cm2 and I : 4cm, findr.
2T Achord PQ of a circle of radius 10 cm subtends an
angle of A radians at the centre O. Calculate theU2exact areas of the two parts into which the chordPQ divides the sector POQ.
22 In the diagram, the circle has centre O and radius r.Angle AOB is g radians and C is the mid-pointof OB. The length of AC is l.
a Express 12 in terms of r and 0.
b Given that I : !r, calanlate the value of g,
correct to 3 decimal places.
c Given thatr :2cn, calculate the area of theshaded region, giving your answer correctto 2 decimal places.
202
29 i sketchthegraph oIy: sinrforvalues of rsuchthat0o <x<720".ii Sketclr, on the same diagram, the graph of y : sin 11, for values of r such
that0o <x<720".
iii State the number of solutions of the equation
sinr: sinlrfor values of r such that 0o < x <720".
iv specify the transformation which transforms the complete graph ofu : sin x (i,e. the graph drawn for all values of x) to ttre complete graph ofi:snir.
v I - IocRI
30 f(r):5sin3ro, 0<x<180.a sketch the graph of. f.(x),indicating the value of x ateach point where the
graph intersects the x-axis.
c
31 a
write down the coordinates of all the maximum and minimum points off(x).
Calculate the values of r for which f.(x) :2.5. IEDEXCELI
Find all the solutions of the equation
sin (3r * 45"):9.7in the interval -90o < r ( 90o, giving your answer to the nearest 0.1o.
No credit will be giaen for simply reading aalues from a graph.
Describe a sequence of geometrical transformations that maps the curvey : sin r onto the curve y : sin (3r + 45"). tAeAI
207
7 Solve the equationS% - 8(3') :0.
8 lf 7v : 3", show lhaly : kx for some constant k which is to be determined.
9 If 8v : 5', show thaty : kx f.or some constant k and find the value of k.
10 a If log13 + log xy - log3x : O,find an equation involving logx and logy.
b Hence find y in terms of x.
11 a If log.l.2 - log xy + Loglx2 : 0, find an equation involving log r and (ogy.
b Hence findy in terms of r.
12 a Write down, in its simplest form, the common difference of the arithmetic
log23 * log29 *log227 + ...b Show that the sum of the first ten terms of A is 55 log2 3.
1-3 Find the value of x for which 23x +"1 - 3'+ 2, giving3 significant figures in youranswer.
1 Express as a single logarithm.
5 If log2 x : \2 then find the following:a log2r3 b log216x
5 Solve the following equations:
d logls (3x + 11 :2B log,15 : 3
b 42'-1:65e logT(x-3):8h log3 9 : logle r
a log2 + 1og5
d log 3 + log 100
e 21og4 + Iog2
Evaluate the following.a log5 25
d tog, (*)
Write aasalogarithm.a 1,V:4
c log2li
c logls (5x) :6t Log,S:4i log5 x: Logd2
c 2Log3
f log48 - log 8i log5+log6-1o910
lo961
logr(|)
b log 20 - log4e log9+log9h 3log2*Log4
b log21,6
e lo91610000
b 6o:17
c
f
[Hint Remember '102 :100 <+ log1e L00 : 2'l
c 7o:3
213
4 Express the following in terms of log a,Iogb andlogc.a logab2
d Los&c
b logc2a
" tog4a
logi6lblog-a
c
f
5 Find.r, correct to 3 significant figures.
a 5':17 b 3':8 c 11,': 100 d 2* - t :5
Solve the equations
alog2(x+5)-Iog2x:3 blog3(x+11)-logr(x-t):4c log5 Gx + 47) - logr (x + 1) :2 d Log,7 :2
_z t,7x+107 a Simpltf1?.x'I 5x
b Find the value of r for which \og2(x2 * 7x * t0) - logz @2 + 5x) :3.
8 Given thatb : lo& 27, express in terms of b:
a togoS b Log,(9a)
9 Given thatb:Iogo2, express in terms of b:
a logo8 b Iog,(1,6a)
10 Given that 5 * 3 log2 x : log2y,show that y : 32x3.
11 a Given that 1 + 2logsx:logt!, show thaty:3x2.b Hence, or otherwise, solve the equation
7 + 2Logsr: logs Vx - 2)
12a
b
c Iog(4a2)
Show that log" m,Iogomn andlogmn2 are three successive terms of anarithmetic sequence whose common difference islogon.Given that mnz : a, show that the sum of the first 5 terms of the arithmeticsequence with first term logo m and common difference log,on is 5.
Given that
2log2x : k andlogr(Zx) : k + 4
find the value of r.
214
1 Express as a single logarithm in its simplest form
log2+2log18 -ltog36
a Show that log2 8 : 3.
b Find the value of
i 1og2 8a
11rii tog2 (,m,)
3 Given that p : logq 16, express in terms of p,
a logr2,
b logr(8q).
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4 a Write down the exact value of r given that 4' : 8.
b use logarithms to find y, correctto 3 decimal places, when 5v: 10. tocRl
5 It is given that ln x : p + 2 andlny :3p.Express each of the following in terms of p:
[nr: log"x]
a ln(xy),
b ln(x3),
. '" (i)
7 The variable r satisfies the equation3,.Ab + 1 - 6)c + 2.
By taking logatithms of both sides, show that r : 1ot'.log 8
y2+4x+g5 a Simolifv ""
- f ---J x.*xb Find the value of x for which logr(r.., * 4x * 3) - logz (x2 + tg1 :4.
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9ab
L0ab
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Solve the equation
f+4x2-9x-6:0,giving each root in an exact form.
Given that
2ln(x + 2) + lnff : ln (13x + 6),
prove that
x3+4x2-9x-6:0.Hence solve the equation
Zln(x + 2) + lnr : ln (13x + 6). IOCR]
Given that 3 * 2log2x:logz!, show thaty :8*.Hence, or otherwise, find the roots a and B, where o1 F, of the equation
3 + 2Iog2x : logzf. x - 3).
Show that log2 q.: -2.Calculate logr$, giving your answer to 3 significant figures. IEDEXCEL]
Find the smallest integer satisfying the inequality 2 > 100643.
Find the exact solution of the equation
In(2A + 1) - In4: 1.,
giving the answer in terms of e. lReminder lny: Log.yl IOCR]
Given that
Iogx:logo5 * 2log"3,
where a is a positive constant, show that r : 45.
i Write down the value of Log22.
ii Given that
logry : loga2,
find the value of.y. IAQA]
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Find the constants A and B in the following.a (x*Z)(Ax +B): x2+7x+']-,0 b (x+1)(Ax+ B):2*+5x+3c (r* 2)(Ax+B): 3x2+8x+ 4 d (x-2)(Ax+B): 3*-5x-2e (2x + 1)(Ar + B): 6f +7x+2 f (2x + 3XAx+ B) = 6x2 +7x-3g @- 1)(Ax+B): x3+2x2-x-2 h (f + 3)(Ax+B):3x3-f *9x-3
Find the constants A, B and C.
a (x * 1,)(Ax2 * Br * C) :2x3 + 13x2 +']-,6x -15
b (r + 2)(Ax2* Br * C) : x3 + 7f + 1,6x + 12
c (tr - 1)(Atr2 * Br* C) : x3 * f - x -'1,d (r+3)(Ax2 *Bx* C):2x3+9*+llx+5e (x - 2)(Ax2 * Bx * C):4x3 - 9x2 + 5x - 6
Use the factor theorem to factorise the following cubics as far as possible:
a f(x'):'x3-7x-6c f(r):x3-3x*2e f(r):f +x2-2gf(x):i3-5f+5x+3i f(r) :2f -t 2x2 - \lx * 3
bf(r):'r3-7x*6d f(r) :.f + x2 - 6x
t f(x):r9+ x2-2x-8hf(x):f+4x2-x-4i f@):4f *1012 +x-6
b 12x3 _ 37x2 _t 2gx _ 6:0d,f-x:0
Find a given that:
a (r - 2) is a factor of f(r) : x3 + af + 3x + 2b (r + 1) is a factor of f(r) : i3 - 2x2 * ax -17
c (x - 1) is a factor of f(x) :2x3 + Sxz - 3x * a
d (r + 3) is a factor of f(r) : flx3 - * + 4x - 6
Find a andb given thata (x - 1) and (x - 2) are factors of f@) :2x3 + af + bx - 6
b (r + 1) and (r - 5) are factors of f(r) : ax3 -'1,4x2 + bx + 10
c (r * 3) and (x - 4) are factors af f@) :3f - 7f + a* * bx + 24
d (x + 2) and (3r + 1) are factors of f(x) :3f + axz + bx - 2
e (x - 1) and (2x + 3) are factors off(x): ax3 + 3x2 + bx - 3
Enda giventhat (r + 4) is a factorof f(x) : f +8x2 + ax* 12 andhencefactorise f(x) completely.
I! Kx) : f + 3f + x - 1, find f(1) and (- 1). Hence factorise f(r).
Sftrow that (r - 2) is a factor of f(x) : x3 - 4x2 + x* 6 and hence solve f(r) : 0.
Fnd the three solutions to each of the following equations (giving youranswers as fractions where necessary):
e 10ri-29x2*25x-5:0c 4f-72x2*5r:0
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