# Thread: exact value equation. identity for next step?

1. ## exact value equation. identity for next step?

hi everyone. I am stuck on which identity to apply next. I know what the next step should look like but I cant get there. could you show which idntity to apply and how? thanks

$\displaystyle tan2x-cotx=0$

$\displaystyle \frac {2tanx}{1-tan^2x}-cotx=0$

$\displaystyle (\frac {1-tan^2x}{1})\frac {2tanx}{1-tan^2x}=cotx(\frac {1-tan^2x}{1})$

$\displaystyle 2tanx=cotx-cotxtan^2x$

this is where I get stuck. how do you get to the next step? it should look like this.

$\displaystyle 2tanx=cotx-tanx$

2. Try writing $\displaystyle \displaystyle \cot{x} = \frac{1}{\tan{x}}$.

3. What is the definition of tan and cot?

If you still don't see it, why not express tan and cot as sin and cos?

EDIT: Woops, a little too late

4. o geeze... i see it now. thanks guys. really fast reply!
I always get stuck on simple stuff. I over think things to much...

it was good to learn how to use latex tho!