bonjour,
f (x) = 3 x
f ( 0.5) = 3 *0.5 = 1.5
g (x) = 2 x - 6
2 x - 6 = 0
2 x = 6
x = 3
g (3) = 0
h (x) = - 3 x² + 1
h ( 1) = - 3 + 1 = - 2
h ( 0) = 1
h ( - 3 x² + 1 ) = x
h ( 2 ) = - 3 ( 2) ² + 1 = - 12 + 1 = - 11 donc vrai
h ( -5) = - 3 ( - 5 )² + 1 = - 3 *25 + 1 = - 75 + 1 = - 74
