I need help with hw again UG, lol.

I'm using the half-angle identity formulas to solve equations.

so far i need

Sin 67.5 (degrees)

It would be hard to write out the formula and such, but i've gotten it down to


it looks crazy there, but is pretty straight forward on paper, my problem comes with just going through the math, how the eff do i solve for that? i know i set up the problem correctly (the only potential problem is the positive or negative with the cos of 135. It's negative but...

the formula says 1 - cosx, so 1 - (-SQRT(2)/2) = 1 + SQRT(2)/2)

<edit>: OH. forgot to mention... it needs to be an exact answer, no calculator ez-ness here
Last edited by Shanky2563 at Mar 3, 2009,