hey guys help me to prove this one (sintheta-tantheta)square=(tan square theta)(cos theta-1)square

(sin{\theta}-tan{\theta})^{2}=sin^{2}{\theta}-2tan{\theta}sin{\theta}+tan^{2}{\theta}

Use the identity: sin^{2}{\theta}=tan^{2}{\theta}cos^{2}{\theta}

Hammer it into shape.

When it looks like:

tan^{2}{\theta}(cos{\theta}-1)^{2}=tan^{2}{\theta}cos^{2}{\theta}-2tan^{2}cos{\theta}+tan^{2}{\theta}

you're there.