Question

F(x)= x²-4 dan g(x) = 2x-6,jika (fog)(x)= -4,nilai x =

Answer 1

 f(x) = x²-4
g(x) = 2x-6

(fog)(x) = f(g(x))
             = (2x-6)² -4
             = 4x²-24x+36-4
             = 4x²-24x+32

(fog)(x) = -4
        -4 = 4x²-24x+32
         0 = 4x²-24x+36
         0 = 4(x²-6x+9)
         0 = 4(x-3)²

maka x = 3