bonjour
f ( x) = - 15
4 x² + 16 x - 15 = - 15
4 x² + 16 x - 15 + 15 = 0
4 x² + 16 x = 0
4 x ( x + 4 ) = 0
x = 0 ou - 4
f ( x)= 1
( - 4 ) ( x - 2 )² + 1 = 1
( - 4 ) ( x - 2 ) + 1 - 1 = 0
- 4 x + 8 = 0
- 4 x = - 8
x = 2
f (x) = 0
( 2 x - 5 ) ( 2 x - 3 ) = 0
x = 5/2 ou 3/2