jika g(x)=3x+2 dan (fog)(x)=-4-9x maka f(x+1)=

jawab

g(x) = 3x + 2

(fog)(x) = 4 - 9x
f{ g(x) } = 4 - 9x
f (3x +2) = 4 - 9x
f(x) =  4 - 9 (1/3 ( x- 2))
f(x) = 4 - 3(x - 2)
f(x +1) = 4 - 3 (x +1 - 2)
f(x + 1) = 4 - 3(x - 1)
f(x + 1)= 4 - 3x + 3
f(x  + 1)= 7 - 3x