Prove this version of L'Hopitals theorem

1. Nov 15, 2008

marlen19861

I need to prove this version of L'Hopitals theorem.

If limf(x)=limg(x)=infinity (as x goes to infinity) then lim[f(x)/g(x)]=lim[f'(x)/g'(x)] (as x goes to infinity)

Thank you

2. Nov 15, 2008

HallsofIvy

Staff Emeritus
Re: L'Hopital

Have you tried applying L'Hopital's rule to (1/g(x))/(1/f(x))?