Question

Jika (fog)(x)=x^2+7x+4 dan g(x)=x+2,maka tentukan nilai f(x)!

Answer 1

G(x) = px + q
(fog)(x) = ax^2 +bx +c

g(x) = x+2
p = 1 ; q = 2

(fog)(x) = x^2 +7x+4
a = 1 ; b = 7 ; c = 4

f(x) = a{(x-q)/p}^2 +b{(x-q)/p} +c
f(x) = 1{(x-2)/1}^2 + 7{(x-2)/1} + 4
f(x) = (x-2)^2 + 7x-14 +4
f(x) = x^2 -4x +4 +7x-10
f(x) = x^2 +3x -6