Réponse :
1/ avec 1 : avec -2: avec 2 :
1-6 = -5 -2 -6 = -8 2-6 = -4
-5*1= -5 -8 * (-2)= 16 -4*2 = -8
-5 + 9 = 4 16+9 = 25 -8 + 9 = 1
on obtient 4 on obtient 25 on obtient 1
2/ f(x) = ((x - 6 ) *x) + 9 = x ( x- 6 ) +9
f(1) = 1 ( 1-6 ) +9 = 1*1 -1*6+9 = 1-6+9 = 4
f(-2) = -2 ( -2-6 ) +9 = -2*(-2)-(-2)*6+9 = 4- (-12) +9 =4+12+9 = 25
f( ) = 3( 3-6 ) +9 = 3*-3 + 9 = -9+9 = 0
3 / f(x) = ( x- 3) ² = x²- 2*x*3 + 3² = x²-6x +9 =x ( x- 6 ) +9
on vérifie :
x ( x- 6 ) +9 =x*x -x*6+9 = x²-6x + 9
