# distinct value of

• May 19th 2008, 10:29 PM
afeasfaerw23231233
distinct value of
given $cos ^2 \frac {4k\pi\pm\pi}{12}$
how can i find the three distinct values of it beside putting k = 1,2,3,4,5..... to evaluate it's value to see they are the same or not?
• May 19th 2008, 10:38 PM
Jhevon
Quote:

Originally Posted by afeasfaerw23231233
given $cos ^2 \frac {4k\pi\pm\pi}{12}$
how can i find the three distinct values of it beside putting k = 1,2,3,4,5..... to evaluate it's value to see they are the same or not?

note that $\cos^2 \left( \frac {4k \pi \pm \pi}{12} \right) = \frac {1 + \cos \frac {(4k \pm 1) \pi}6}2$

it should be easier for you to find the values when k = 1,2,3,4.... now

(hope you're good with reference angles :p)