Question

Soal tentang komposisi fungsi
1. Diketahui f(x)=3x+4 dan g(x)=2x²-x+5.
(Gof) (x) = ... ?

2. Diketahui f(x)=4x-1 dan g(x)=5x+6
(Fog) (-2) = ... ?

Answer 1

1. (gof) (x) = 2(3x + 4) ^2 - (3x + 4) + 5
= 2(9x^2 + 24x + 16) - 3x - 4 + 5
= 18x^2 + 48x + 32 - 3x - 4 + 5
= 18x^2 + 45x + 33
2. (fog) (x) = 4(5x + 6) - 1 = 20x + 24 - 1 = 20x + 23
(fog) (-2)= 20x + 23 = 20(-2)+23 = -40 + 23 = -17