$\displaystyle sec^2x * tanx = 2tanx$

in [0, 360) interval

find degree of x

Do I subtract 2tanx then use tan^2+1 = sec?

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- Jan 13th 2009, 04:46 PMshanzwhaattrig
$\displaystyle sec^2x * tanx = 2tanx$

in [0, 360) interval

find degree of x

Do I subtract 2tanx then use tan^2+1 = sec? - Jan 13th 2009, 04:55 PMvincisonfire
$\displaystyle \frac{sin(x)}{cos^3(x)}= 2\frac{sin(x)}{cos(x)} $

$\displaystyle \frac{1}{2} = cos^2(x) $

$\displaystyle \pm \sqrt{\frac{1}{2}} = cos(x) $

Can you find the answer now? - Jan 13th 2009, 05:01 PMshanzwhaat
Yes, thanks.. but i did it like this and it worked....

$\displaystyle sec^2x * tanx = 2tanx$

and i divided tanx from the both sides and got..

$\displaystyle tan^2x+1=2$ then..

$\displaystyle tan^2x=1$and finally..

$\displaystyle tanx=+/-1$

That way can work too right? - Jan 13th 2009, 05:04 PMvincisonfire
Of course it is even better. I have a tendency to complicate things.

- Jan 13th 2009, 05:05 PMshanzwhaat
Hhaha okay.. thank you so much for your help, it actually helped me to get to that step haha.