(Sin a -cos a)2( в квадрате)+ 2sin a cos a

Question

(Sin a -cos a)2( в квадрате)+ 2sin a cos a

Answer 1

(sina-cosa)ˇ2 +2.sinacosa=sinˇ2a -2.sina.cosa +cosˇ2a +2.sinacosa=
=sinˇ2a + cosˇ2a = 1