That is what I meant. I wanted to point out that sqrt is more expensive compared to squared and you could just square the whole thing without affecting the resu

That is what I meant. I wanted to point out that sqrt is more expensive compared to squared and you could just square the whole thing without affecting the results too much. cos(theta) and cos^2(theta) are pretty close and monotonous between 0 and pi/2: http://www.wolframalpha.com/input/?i=cos%28theta%29+vs+cos%28theta%29*cos%28theta%29 http://www.wolframalpha.com/input/?i=cos%28theta%29+vs+cos%2...