Prove each identity. 1.->  cos^2x-sin^2x=2cos^2x-1 identites include-  cscx=1/sinx , secx=1/cosx , cotx=1/tanx , tanx=sinx/cosx , cotx=cosx/sinx , sin^2x+cos^2x=1

1 Answer | Add Yours

lfryerda's profile pic

lfryerda | High School Teacher | (Level 2) Educator

Posted on

If you have more than one question you need to make separate posts.

In order to prove this identity, you need to start with one side, and then using existing identities, end up at the other side of the identity.

`LS=cos^2x-sin^2x`   use `sin^2x+cos^2x=1`

`=cos^2x-(1-cos^2x)`   remove brackets

`=cos^2x-1+cos^2x`  collect like terms



The identity has been proven.

We’ve answered 317,744 questions. We can answer yours, too.

Ask a question