[ATTACH=full]2220[/ATTACH]

you know that sin(0)=0 sin(0)*sin(0)=sin^2(0)=0 same will be for any power sin^100(0)=0 cos(0)=1 same reasoning as above cos^100(0)=1 so, sin^100(0)+cos^100(0)=1 0+1=1 1=1 ->true