Question

FKFI

g(x+2) = 2x+1 daqn fog(x) = 3x² - 2x + 1, maka nilai f(-1) = ...

Answer 1

G(x + 2) = 2x + 1
g(x + 2 - 2) = 2(x - 2) + 1
g(x) = 2x - 4 + 1 = 2x - 3

(fog)(x) = 3x² - 2x + 1
f(g(x)) = 3x² - 2x + 1
f(2x - 3) = 3x² - 2x + 1
f(2x - 3 + 3) = 3x(x + 3)² - 2(x + 3) + 1
f(2x) = 3(x + 2)² - 2(x + 3) + 1
f(x) = 3 - 2 + 1
f(-1) = 3 - 2 + 1
f(-1) = 3.1 - 2.1 + 1 = 3 - 2 + 1 = 2