# Trig Proof

• Apr 9th 2010, 02:28 PM
sigma1
Trig Proof
i have been trying to crack this but i have had no luck. hope someone can help.

$(sin4x + sin2x)/(cos4x+cos2x) = tan3x$

the X varibale is actually (pie), i just could not type it into the window...
• Apr 9th 2010, 03:19 PM
Quote:

Originally Posted by sigma1
i have been trying to crack this but i have had no luck. hope someone can help.

$(sin4x + sin2x)/(cos4x+cos2x) = tan3x$

the X varibale is actually (pie), i just could not type it into the window...

What exactly are you trying to crack?

$\sin(n \pi) = 0$ for $n = \pm 1$, $\pm 2$, ...

$\tan(n \pi) = 0$ for $n = \pm 1$, $\pm 2$, ...

Hence both sides = 0.
• Apr 9th 2010, 03:23 PM
\pi $\pi$
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