Diketahui fungsi f dan g ditentukan oleh f(x) = 3x^2 + x – 7 dan g(x) = 2x + 1. Rumus fungsi (f ° g)(x) = …

(f•g)(x) = f(g(x))
= 3(2x+1)² + (2x+1) - 7
= 3(4x²+4x+1) + 2x + 1 - 7
= 12x²+12x+3+2x+1-7
= 12x² + 14x - 3

f(x)= 3x² + x - 7
g(x)= 2x + 1

(fog)(x)= f(g(x))
(fog)(x)= f(2x + 1)
(fog)(x)= 3(2x+1)² + (2x+1) - 7
(fog)(x)= 3(4x²+4x+1) + 2x + 1 - 7
(fog)(x)= 12x² + 12x + 3 + 2x - 6
(fog)(x)= 12x² + 12x + 2x + 3 - 6
(fog)(x)= 12x² + 14x - 3