- #1

gorlitsa

- 2

- 0

## Homework Statement

[itex]\stackrel{lim}{x\rightarrow 0}\frac{cos^2x-1}{2xsinx}[/itex]

## Homework Equations

[itex]\stackrel{lim}{x\rightarrow 0}\frac{1-cosx}{x}=0[/itex]

[itex]\stackrel{lim}{x\rightarrow 0}\frac{sinx}{x}=1[/itex]

## The Attempt at a Solution

I found this problem online (and can't remember where). It was in a limits section, so it can be solved without using l'Hopitals rule. I gave it to my class today, and then we all got stuck. We know the answer is -.5 but can't get it algebraically. Any advice?