# Homework help!

1. Oct 6, 2004

### Maria

Can someone help me with this:cos^2x = 2cosxsinx?
X E 0,360..
I really haven`t understood this trigonomy stuff yet.. :yuck:

2. Oct 6, 2004

### matt grime

Did you see that sticky about posting homework?

Hint: forget trig for now, and simplify

a^2=ab.

3. Oct 6, 2004

### Motifs

Hi, Maria, I am Susan, What matt told you to do is something like this:
cosx(cosx-2sinx) =0
cosx=0 OR tanx=1/2

Last edited: Oct 6, 2004
4. Oct 7, 2004

### Maria

hi again

Can you explain it to me a bit more?

I need to understand the whole prosess, because I have to explain it to someone else on thursday.. I need 4 angles..

5. Oct 7, 2004

### Zurtex

What you basically have is:

$$a^2 = ab$$

You can wright this is:

$$a^2 - ab = 0$$

$$a(a - b) = 0$$

This tells you that either $a$ is 0 or $a - b$ is 0, right? Well try and follow that procedure out with your trig functions.

6. Oct 11, 2004

### Maria

Thanks

I got it right Thanks a lot

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?