Question

(sin a + cos a)^2- sin2α= 1

Answer 1

sin^2 a + cos^2 a = 1

2sin a*cos a = sin 2a

(sin a + cos a)^2- sin2α= sin^2 a + 2sin a*cos a + cos^2 a - sin2α= 1 + sin 2a - sin 2a = 1