So we had a huge test in class, and everyone bombed. No one passed, at all. So we're doing a make up test right now, and its the exact same test, with the answers already on it, and we need to show the work of how to achieve the answer.

I'm stuck on one question, and supposedly it's "really easy" but I can't seem to figure it out. So I was hoping someone on here can show me the work on how to achieve the answer.

It seems like a quick and easy one, according to everyone, so it shouldn't take more than a moment of your time.

Here's the problem

2cos(squared)22.5(deg)-1

The cosine is squared and the 22.5 is in degrees. The answer is supposed to be sqrt2/2 so square root of 2 over 2.

If someone can show me the work to do this, I would be forever grateful, and may just give you +K or help you out with something you need!

-Thanks!