diketahui fungsi f(x) = x+3 dan fungsi komposisi (g 0 f)(x) = x² + x - 5 tentukan g(x)

f(x) = x + 3
g(f(x)) = x² + x - 5
g(x + 3) = (x + 3)² - 5(x + 3) + 1
g(x) = x² - 5x + 1

misalkan x+3=t maka x=t-3
(g0f)(x) = x^2+x-5
g(f(x)) = x^2+x-5
g(x+3)= x^2+x-5
g(t) = (t-3)^2 +(t-3) -5
g(t) = t^2-6t+9+t-3-5
g(t) = t^2-5t+1
jadi, g(x)=x^2-5x+1