Diketahui f(x) = x² + 3x -4 dan g (x) = x-4 tentukan (fog) (x) ?

fog(x)
= f(g(x))
= f(x - 4)
= (x - 4)² + 3(x - 4) - 4
= x² - 8x + 16 + 3x - 12 - 4
= x² - 5x 

(fog)(x)=f(g(x))
             =f(x-4)
             =(x-4)²+3(x-4)-4
             =x²-8x+16+3x-12-4
             =x²-5x