Question

Mohon bantuaannya
f(x)=2x+1 dan (fog) (x+1) = -2xkuadrat -4x-1 . nilai g(-2) = .. ?
a. -5
b. -4
c. -1
d. 1
e. 5

Answer 1

f(x)=2x+1 dan (fog) (x+1) = -2x^2 - 4x - 1(fog)(x+1) = -2x^2-4x-1
f(g(x+1)) = -2x^2-4x-1
2g(x+1) + 1 = -2x^2-4x-1
2g(x+1) = -2x^2-4x-2
g(x+1) = -x^2 - 2x - 1
          = -(x^2 + 2x + 1)
          = -(X+1)(X+!)
g(x)    = -(x)(X)
 g(-2)  = -(-2)(-2)
         = -4
Jawabannya (B)