Question

2cos^2 x=1+2sin^2 x решите

Answer 1

$2cos^2x=1+2sin^2x\ 2cos^2x-2sin^2x=1\ 2(cos^2x-sin^2x)=1\ \ cos2x=0.5\ 2x=pm frac{pi }{3} +2pi n,n in mathbb{Z}\ \ x=pm frac{pi }{6} +pi n,n in mathbb{Z}$