Question

Tentukan rumus untuk fungsi f(x) jika dketahui: g(x)=2x+1 dan (f o g)(x)= x²+x

Answer 1

G(x) = 2x + 1
g^-1(x)= 1/2 x - 1/2
.
f(x) = (fog) o g^-1 (x)
f(x) = (1/2 x - 1/2)² + (1/2 x - 1/2)
f(x) = 1/4 x² - 1/2 x + 1/4 + 1/2x - 1/2
f(x) = 1/4 x² - 14
f(x) = 1/4 (x² - 1 )