Di ketahui f(x)=xkuadrat,g(x)=x-3 dan h(x)=5x tentukan (fo(goh))(x)

f(x) = x^2, g(x) = x - 3, h(x) = 5x
ditanyakan (fo(goh))(x) ??
penyelesaian:
Misal k(x) = (g o h) (x)
=======> = g (h(x))
=======> = g (5x)
=======> = 5x - 3
(fo(goh))(x) = (f o k) (x)
========> = f (k(x))
========> = f (5x - 3)
========> = (5x - 3)^2
========> = (5x - 3) (5x - 3)
========> = 25x^2 - 15x - 15x + 9
========> = 25x^2 - 30x + 9

keterangan : tanda (^) adlah pangkat