# Thread: double angle problems

1. ## double angle problems

Simplify.
1. 2cos^2 4x-1
sin4xcos4x

2. 1-4sin^2x+4sin^4x

The answers to the first is 2cot8x and the second is cos^22x. I would like to see the step by step process.
Help would be appreciated thanks!

2. Originally Posted by andrewsx
Simplify.
1. 2cos^2 4x-1
sin4xcos4x

2. 1-4sin^2x+4sin^4x

The answers to the first is 2cot8x and the second is cos^22x. I would like to see the step by step process.
Help would be appreciated thanks!
And what was wrong with Jhevon's answer? If you have a question about his answer, please respond in the original thread.

And please don't double post. See rule #1 here.

-Dan

3. Sorry, when I logged into the forum, I didn't know where to find my thread from yesterday and any replies that may have accrued. I should check my email from now on so that i can see who replied.

4. Originally Posted by andrewsx
Sorry, when I logged into the forum, I didn't know where to find my thread from yesterday and any replies that may have accrued. I should check my email from now on so that i can see who replied.
When you log in there will be a blue bar near the top of the page with several options on it. Click on "New Posts", which is about 3/4 across the page. This will show you all the posts that have been made since you last logged on.

-Dan