Originally Posted by

**louis** I'm having trouble following along with steps in my notes. Maybe someone can chime in and point me in the correct direction.

The original problem is:

$\displaystyle \displaystyle\lim_{ x\to\frac{\pi}{4} } \frac{1 - tan x}{ cos x - sin x}$

I am stuck trying to get from this step

$\displaystyle \displaystyle\frac{\cos{x} - ( \frac{\sin^2{x} }{ cosx }) }{ cos^2x - sin^2x})$

To

$\displaystyle \frac{(cos^2x - sin^2x }{ cosx }) ( \frac{1 }{ cos^2x - sin^2x})$

Any help is appreciated!