# How to prove the following equation:cos*2(180+x)+tan(x-180)sin(720-x)cosx=cos2x

I have tried solving it but I just can't get it right

How to prove the following equation:cos*2(180+x)+tan(x-180)sin(720-x)cosx=cos2x

I have tried solving it but I just can't get it right

Please start posting anonymously - your entry will be published after you log in or create a new account.

Asked: ** 2017-04-13 15:12:09 +0100 **

Seen: **510 times**

Last updated: **Apr 13 '17**

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.

What does

`cos*2(180+x)`

mean ?Let me guess:

`bool(equ)`

yields`True`

Well...

This is the half of the cake.