je ne compris pas ce exercice m'aident s'il vous plaît​

Bonjour,

1)a• f(0) = 3 ; f(1) = 5 ; f(-4) = -5

g(0) = 0 ; g(1) = -1 ; g(-4) = 4

1)b• f(0) = 3 ; f(-4) = - 5 ; f(1) = 5

g(-3) = 3 ; g(5) = -5 ; g(-5) = 5

2) f(-1) = g(-1)

S = {-1}

3) f(x) = 2x + 3 et g(x) = -x

4)

Vérification :

• Question 1)a :

f(0) = 2×0 + 3 = 3 ; f(1) = 2×1 + 3 = 5 ; f(-4) = 2×(-4) + 3 = -5

g(0) = -0 = 0 ; g(1) = -1 ; g(-4) = -4

• Question 1)b :

f(x) = 3 => 2x + 3 = 3 => 2x = 0 => x = 0

f(x) = -5 => 2x + 3 = -5 => 2x = -8 => x = -4

f(x) = 5 => 2x + 3 = 5 => 2x = 2 => x = 1

g(x) = 3 => -x = 3 => x = -3

g(x) = -5 => -x = -5 => x = 5

g(x) = 5 => -x = 5 => x = -5

• Question 2 :

f(x) = g(x)

2x + 3 = -x

2x + x = -3

3x = -3

x = -3/3

x = -1

On a bien f(x) = g(x) pour x = -1.