Solve cos²x = 2cosxsinx for x in 0 to 360 degrees

[Maria]

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

 

[matt grime]

Did you see that sticky about posting homework?

Hint: forget trig for now, and simplify


a^2=ab.

 

[Motifs]

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

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

 

[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..

 

[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.

 

[Maria]

Thanks

I got it right Thanks a lot