Bonsoir,
1) f(x) = g(x)
x = 4
2) f(x) ≤ g(x)
x€]-oo;4]
3) d1 : y = ax+b
(0;-3) et (2;0)
-3 = b
0 = 2a+b
0 = 2a-3
3 = 2a
3/2 = a
f(x) = 3/2x-3
d2: y = ax+b
(0,4) et (4;3)
4 = b
3 = 4a+b
3 = 4a+4
-1 = 4a
-¼ = a
g(x) = -¼x+4
f(x) = g(x)
3/2x-3 = -¼x+4
3/2x+1/4x = 7
7/4x = 7
7x = 28
x = 4
f(x) ≤ g(x)
3/2x-3 ≤ -¼x+4
3/2x+1/4x ≤7
7/4x ≤ 7
7x ≤ 28
x ≤ 4
