Sagot :
Bonjour
a.
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (- 3) = (- 3 - 1) (11 - (- 3)) + 5 (- 3 - 1)²
f (- 3) = (- 4) (11 + 3) + 5 (- 4)²
f (- 3) = (- 4) * 14 + 5 * 16
f (- 3) = - 56 + 80 = 24
g (x) = 2 (x - 1) (2x + 3)
g(- 3) = 2 (- 3 - 1) (2 * - 3 + 3)
g (- 3) = 2 * (- 4) * (- 6 + 3)
g (- 3) = - 8 * (- 3)
g(- 3) = 24
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (- 2) = (- 2 - 1) (11 - (- 2) + 5 (- 2 - 1)²
f (- 2) = (- 3) * (11 + 2) + 5 * (- 3)²
f(- 2) = - 3 * (13) + 5 * 9
f (- 2) = - 39 + 45
f (- 2) = 6
g (x) = 2 (x - 1) (2x + 3)
g(- 2) = 2 (- 2 - 1) (2 * - 2 + 3)
g(- 2) = 2 (- 3) (- 4 + 3)
g(- 2) = - 6 * (- 1)
g (- 2) = 6
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (- 1) = (- 1 - 1) (11 - (- 1)) + 5 (- 1 - 1)²
f (- 1) = - 2 * (11 + 1) + 5 * (- 2)²
f (- 1) = - 2 * 12 + 5 * 4
f (- 1) = - 24 + 20
f (- 1) = - 4
g (x) = 2 (x - 1) (2x + 3)
g ( - 1) = 2 (- 1 - 1) (2 * - 1 + 3)
g(- 1) = 2 * (- 2) * (- 2 + 3)
g (- 1) = - 4 * 1 = - 4
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (0) = (0 - 1) (11 - 0) + 5 (0 - 1)²
f (0) = - 1 * 11 + 5 * (- 1)²
f (0) = - 11 + 5
f (0) = - 6
g (x) = 2 (x - 1) (2x + 3)
g (0) = 2 (0 - 1) (2 * 0 + 3)
g(0) = 2 * (- 1) * 3
g(0) = - 2 * 3 = - 6
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (1) = (1 - 1) (11 - 1) + 5 (1 - 1)²
f (1) = 0 * 11 + 5 * 0
f(1) = 0
g (x) = 2 (x - 1) (2x + 3)
g(1) = 2 (1 - 1) (2 * 1 + 3)
g(1) = 2 * 0 * 2 + 3
g (1) = 0
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (2) = (2 -1) (11 - 2) + 5 (2 - 1)²
f (2) = 1 * 9 + 5 * 1²
f(2) = 9 + 5
f (2) = 14
g (x) = 2 (x - 1) (2x + 3)
g(2) = 2 (2 - 1) (2 * 2 + 3)
g (2) = 2 * 1 * (4 + 3)
g (2) = 2 * 7 = 14
f (x) = (x - 1) (11 - x) + 5 (x - 1)²
f (3) = (3 - 1) (11 - 3) + 5 (3 - 1)²
f (3) = 2 * 8 + 5 * 2²
f (3) = 16 + 5 * 4
f (3) = 16 + 20 = 36
g (x) = 2 (x - 1) (2x + 3)
g (3) = 2 (3 - 1) (2 * 3 + 3)
g (3) = 2 * 2 * (6 + 3)
g(3) = 4 * 9 = 36.
b. Quel que soit le nombre choisi pour x les fonctions f (x) et g(x) obtiennent toujours le même résultat.