Question

Di ketahui g(x)=2x + 1 dan
(f°g) (x) = 6x² + 4x + 7. rumus f(x) adalah ........................ gunakan dengan caranya.
mtk SMK/SMA.

Answer 1

G(x) = 2x + 1
fog(x) = 6x² + 4x + 7
f { g(x) } = 6x²+ 4x + 7
f (2x+1)  = 6x² + 4x + 7
.
f(x)= 6{1/2(x-1)}² + 4{ 1/2 (x-1)} + 7
f(x) = 6(1/4) (x-1)² + 2(x-1) + 7
f(x) = 3/2 (x-1)² + 2(x-1) + 7
f(x) = 3/2(x²-2x+1) + 2x - 2 + 7
f(x) = 3/2 x² - 3x + 3/2 + 2x + 5
f(x) = 3/2 x² - x + 13/2
f(x)= 1/2 (3x²- 2x + 13)