Jika f(x)= -3x +1 dan g(x)= 2x/x-1 maka (fog)invers (x) adalah

fog(x)
= f(g(x))
= -3(2x/(x-1)) + 1
= (-6x + x-1)/(x+1)
= (-5x+1)/(x+1)
y =(-5x+1)/(x+1)
xy + y = -5x+ 1
xy + 5x = 1 - y
x(y+5) = 1- y
x = (1-y)/(y+5)
fog invers x = (1-x)/(x+5)