Réponses

2013-03-31T21:44:14+02:00
A) F : x -----> -3x
F(x) = -3x

> f(-1) = -3(-1)
f(-1) = 3

f(1) = -3(1)
f(1) = -3

f(0) = -3(0)
f(0) = 0

f(4) = -3(4)
f(4) = -12

f(2/3) = -3(2/3)
f(2/3) = -2 [ j'ai simplifié 3 et 3 par 3, reste 1 ]

f(3/2) = -3(3/2)
f(3/2) = -9/2

B) f(x) = -3x

> -3x = 15
x = -15/3
x = -5

-3x = -8
x = 8/3