# Math Help - proving an identity

1. ## proving an identity

can someone help me prove this identity?

(tan^2x)-(sin^2x)=(sin^2x)(tan^2x)

2. Originally Posted by wisezeta
can someone help me prove this identity?

(tan^2x)-(sin^2x)=(sin^2x)(tan^2x)
Hi

Start proving from the right hand side

$\tan^2x-\sin^2x=\frac{\sin^2x}{\cos^2x}-\sin^2x$

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

$=\frac{\sin^2x}{\cos^2x}(\sin^2x)$

$
=\tan^2x\sin^2x
$

Proved .

3. (tan^2x)-(sin^2x)=(sin^2x)(tan^2x)

an identity treated as an equation, the graph is shown below