SOLUTION: We are proving identities and my book only has three examples. So I was hoping I could get some help solving a problem my teacher assigned on our test. I failed to answer it correc

Algebra ->  Trigonometry-basics -> SOLUTION: We are proving identities and my book only has three examples. So I was hoping I could get some help solving a problem my teacher assigned on our test. I failed to answer it correc      Log On


   



Question 309689: We are proving identities and my book only has three examples. So I was hoping I could get some help solving a problem my teacher assigned on our test. I failed to answer it correctly, but he will be doing similar problems on our final exam.
cos^2 x cos^2 y = -sin(x+y) sin(x-y)
If you could show the steps and explain them I'd greatly appreciate it.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Unfortunately, cos^2 x cos^2 y = -sin(x+y) sin(x-y) is NOT an identity. You must be missing a symbol either in between the terms cos^2 x and cos^2 y or in between the terms -sin(x+y) and sin(x-y). Please repost with the correct problem.