given $\displaystyle cos ^2 \frac {4k\pi\pm\pi}{12}$
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?
given $\displaystyle cos ^2 \frac {4k\pi\pm\pi}{12}$
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?