Diketahui f(x)=√x+2 dan g(x)=x²-6 a. Tentukan (g•f)(x) b. Hitunglah (g•f)(4)

a.
g o f (x) = g(f(x))
g o f (x) = g(√x +2)
g o f (x) = (√x + 2)² - 6
g o f (x) = (x + 4√x + 4) - 6
g o f (x) = x + 4√x - 2

b. g o f(4)
= x + 4√x - 2
= 4 + 4√4 - 2
= 4 + 8 - 2
= 10