Trig integrals. sqrt(1-cos2x)dx
1 - cos 2 x = 1 - ( cos² x - sin² x ) = 1 - cos² x + sin² x = sin² x + sin² x = = 2 sin² x\(\int { \sqrt{2sin ^{2} x} } \, dx = \sqrt{2} \int {sinx} \, dx =\)= - √2 cos x + C
