Tentukan nilai a jika diketahui f(x) = 3xkuadrat - 2x + 5 ; g(x) = 1-5x ; (g○f) (a) = 1

f(x) = 3x² - 2x + 5
g(x) = 1 - 5x

(g•f)(x) = g(f(x))
= 1 - 5( 3x² - 2x + 5 )
= 1 - 15x² + 10x - 25

(g•f)(a) = 1
1 - 15a² + 10a - 25 = 1
15a² - 10a + 25 = 0
3a² - 2a + 5 = 0
(3a-5)(a+1) = 0
a = 5/3 atau a = -1