fungsi komposisi: dik: f(x) = x^2 - 4x + 2 g(x) = 3x - 7 tentukan : fog (x) dan gof (5)

f(g(x)) = f(3x-7)
=(3x-6)^2 - 4(3x-7) + 2
= 9x^2- 36x +36 - 12x + 28 + 2
=9x^2 -48x + 66

g(f(5)) = g(5^2-4.5 + 2)
=g(25-20+2)
=g(7)
=3.7-7
=21-7
=14