Question

Jika f (x) = 2x - 3 dan (gof)(x) = 2x + 1. maka nilai g (2) = .... ?
jawab plisss

Answer 1

( g o f ) (x) = (g(fx))
= 2(2x-3) + 1
= 4x-6+1
= 4x-5
g(2) = 4(2)-5
= 3

Answer 2

f(x) = 2x - 3 dan (gof)(x) = 2x + 1

(gof)(x) = g (f(x)) 
2x + 1 = g (f(x))
g (f(x)) = 2x + 1
g(x) = 2(2x - 3) + 1
g(x) = 4x - 6 + 1
g(x) = 4x - 5
g(2) = 4(2) - 5
g(2) = 8 - 5
g(2) = 3