Diketahui f(x)=4x-1 dan (g bundaran f)(x) =5-2x maka g(x) adalah...

jawab

f(x)= 4x  - 1
gof(x)= 5 - 2x
g(4x -1)= 5 - 2x
misal  
y = 4x - 1
4x = y+1
x = 1/4 (y + 1)

g(y) = 5 - 2 { 1/4 (y +1)}
g(y) = 5 - 1/2 (y+1)
g(y) = 5 - 1/2 y - 1/2
g(y) = 4 1/2 - 1/2 y
g(y) = 1/2 (9 - y)
g(x) = 1/2 (9 - x)