F(x)=1/x+1 dan g(x)=x²-1, maka (f o g) (2) adalah

(fog)(x)
= f(g(x))
= f(x² – 1)
= 1/((x² – 1) + 1)
= 1/(x² – 1 + 1)
= 1/x²

(fog)(2)
= 1/2²
= 1/4