11 x1 t01 08 completing the square (2013)
TRANSCRIPT
Completing the Square
Completing the Square2e.g. ( ) 6 7 0i x x
Completing the Square2 6 7x x move the constant
2e.g. ( ) 6 7 0i x x
Completing the Squaremove the constant
2 2 26 3 7 3x x add half the coefficient of ‘x’ squared
2 6 7x x
2e.g. ( ) 6 7 0i x x
Completing the Square
2 6 9 16x x
move the constant
add half the coefficient of ‘x’ squared
23 16x factorise to a perfect square
2 2 26 3 7 3x x
2 6 7x x
2e.g. ( ) 6 7 0i x x
Completing the Square
2 6 9 16x x
3 4x
move the constant
add half the coefficient of ‘x’ squared
23 16x factorise to a perfect square
2 2 26 3 7 3x x
2 6 7x x
2e.g. ( ) 6 7 0i x x
Completing the Square
2 6 9 16x x
3 4x
7 or 1x x
move the constant
add half the coefficient of ‘x’ squared
23 16x factorise to a perfect square
3 4x
2 2 26 3 7 3x x
2 6 7x x
2e.g. ( ) 6 7 0i x x
2( ) 0ii ax bx c
2( ) 0ii ax bx c
2 0b cx xa a
2( ) 0ii ax bx c
2 0b cx xa a
2 b cx xa a
2( ) 0ii ax bx c
2 0b cx xa a
2 b cx xa a
2 2
2
2 2b b c bx xa a a a
2( ) 0ii ax bx c
2 0b cx xa a
2 b cx xa a
2 2
2
2 2b b c bx xa a a a
2 2
22 4b c bxa a a
2
24
4b ac
a
2( ) 0ii ax bx c
2 0b cx xa a
2 b cx xa a
2 2
2
2 2b b c bx xa a a a
2 2
22 4b c bxa a a
2
24
4b ac
a
2 42 2b b acxa a
2( ) 0ii ax bx c
2 0b cx xa a
2 b cx xa a
2 2
2
2 2b b c bx xa a a a
2 2
22 4b c bxa a a
2
24
4b ac
a
2 42 2b b acxa a
2 42
b b acxa
2( ) 6 6 0iii x x
2( ) 6 6 0iii x x
23 0x
2( ) 6 6 0iii x x
23 0x 3
2( ) 6 6 0iii x x
23 0x 3
3 3 3 3 0x x
2( ) 6 6 0iii x x
23 0x 3
3 3 3 3 0x x
3 3 or 3 3x x
2( ) 6 6 0iii x x
23 0x
Exercise 1I; 1adh, 2ch, 3adg, 4bdfh, 5bdf, 6adg, 7bc, 8*
3
3 3 3 3 0x x
3 3 or 3 3x x