Question

упростить 

2sin^2(a)-sin2(a)=0

Answer 1

$2Sin^2 alpha -Sin2 alpha =0$
$2Sin^2 alpha -2Sin alpha Cos alpha =0$
$Sin alpha (Sin alpha -Cos alpha )=0$
$Sin alpha (Sin alpha -Sin( frac{ pi }{2}- alpha ))=0$
$Sin alpha (2Sin( alpha - frac{ pi }{2} + alpha )Cos( alpha + frac{ pi }{2} - alpha ))=0$
$2Sin alpha Sin2 alpha Cos frac{ pi }{2} =0$
$0=0$