Question

Diket f(3x+1)=9x -2 dan (f o g) (x)=-6x² +16. Nilai g(3)= …?

Answer 1

Misal 3x + 1 = p maka x = (p - 1) / 3
f(p) = 9((p - 1) / 3)) - 2
f(p) = 3p - 5
f(x) = 3x - 5
fog(x) = 6x² + 16
3(g(x)) - 5 = 6x² + 16
3(g(x)) = 6x² + 21
g(x) = (6x² + 21) / 3
g(x) = 2x² + 7
g(3) = 2(3²) + 7 = 25