# Math Help - help Prove identities

1. ## help Prove identities

Please guys can you help me prove the following identities

si((n)^(2))θsecθ=sinθtanθ

tan^2 A= ((sin^2A)/(1-si((n)^(2))A))

2-((tan)^(2))A=2((sec)^(2))A-3((tan)^(2))A

Any help would be greatly appreciated. Cheers!

2. Does si(n^2) $\theta$ mean $sin^2 (\theta)$?

For the second one, if you use $tan \theta= \frac{sin \theta}{cos \theta}$ and double angle formulae you should get the answer.

3. #1) sin(x)^2*sec(x) = sin(x) * tan(x)
sin(x) * sec(x) = tan(x)
sin(x) * 1/cos(x) = sin(x)/cos(x)
sin(x)/cos(x) = sin(x)/cos(x)