Ada yang bisa bantu ?

f(x) = x + 1/x = (x^2 + 1)/x
g(x) = x - 1/x
(g o f)(x) = g(f(x))
= f(x) - 1/f(x)
= (x^2 + 1)/x - 1/((x^2 + 1)/x)
= (x^2 + 1)/x - x/(x^2 + 1)
= [(x^2 + 1)^2 - x^2] / x(x^2 + 1)