Question

Diketahui f(x) =2x-5dan g(x) =x pangkatdua-3x+2 tentukan a. Fog(x) b. Fog(-1) c. gof(x) d. gof(2)

Answer 1

A. F•g (x) = 2 (x² - 3 x + 2) - 5
= 2x² - 6x + 4 - 5
= 2x² -6x - 1

B. F•g (-1) = 2x² - 6x - 1
= 2(-1)² - 6(-1) - 1
= 2 + 6 - 1 = 7

C. G•f (x) = ( 2x - 5) ² - 3 ( 2x - 5) + 2
= 4x² - 20x + 25 - 6x + 15 + 2
= 4x² - 26x + 42

D. G•f (2) = 4(2)²-26(2)+42
= 16-52+42 = 6