Posted by **Jake** on Thursday, January 26, 2012 at 9:40pm.

Explain how to do this with steps please.

1. Simplify cos(x-y)+cos(x+y)/cosx

I did some of these so far, don't know if it is correct.

Formula: cosxcosy= cos(x+y)+cos(x-y)/2

cos(x-y)+cos(x+y)/cosx

=cosxcosy/2cosx