Question

Tugas 3 halaman 107 no 4

besok harus di kumpulkan :'(

diketahui fungsi f: R---->R dengan f(x) = - 4x + 2 dan fungsi g: R---->R dengan g(x) = 3x - 7


f(x) = x + 5
g(x) = 2x - 10
tentukan
( fog ) (x)
( gof ) (x)
( gof ) (4)

Answer 1

Ini kalau yg diketahui
f(x) = x + 5
g(x) = 2x - 10

(fog)(x) = f(g(x))
(fog)(x) = f(2x-10)
(fog)(x) = 2x - 10 + 5
(fog)(x) = 2x - 5

(gof)(x) = g(f(x))
(gof)(x) = g(x+5)
(gof)(x) = 2(x+5) - 10
(gof)(x) = 2x +10 - 10
(gof)(x) = 2x

(gof)(x) = 2x
(gof)(4) = 2.4
(gof)(4) = 8