Question

Trig integrals. sqrt(1-cos2x)dx

Answer 1

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