Identity

**jumpman23** · April 27th 2009, 03:21 PM

find an expression that completes the identity,

cos^2x/1-sinx = ?

**skeeter** · April 27th 2009, 04:07 PM

Originally Posted by jumpman23

find an expression that completes the identity,

cos^2x/1-sinx = ?

hint ... $\cos^2{x} = 1 - \sin^2{x}$ ... then factor

**jumpman23** · April 27th 2009, 04:27 PM

I'm still confused about what to do. How do you use this pythagorean identity with this?

**skeeter** · April 27th 2009, 04:30 PM

Originally Posted by jumpman23

I'm still confused about what to do. How do you use this pythagorean identity with this?

factor $1-\sin^2{x}$ and see.

**jumpman23** · April 27th 2009, 04:33 PM

does it end up equaling 1?

**skeeter** · April 27th 2009, 04:42 PM

$\frac{\cos^2{x}}{1 - \sin{x}} = \frac{1 - \sin^2{x}}{1 - \sin{x}} = \frac{(1 - \sin{x})(1 + \sin{x})}{1 - \sin{x}} = 1 + \sin{x}<br />$

Thread: Identity