Question

sin(2П+a)sin(п-a)+cos^2a

 

sin2,5acos1.5a+sin1.5acos2,5a+cos(п/2+4a)

Answer 1

1) $sin(2pi+a)sin(pi-a)+cos^2a = sina*sina+cos^2a = sin^2a+cos^2a = 1$

2)  $sin2.5a*cos1.5a+sin1.5a*cos2.5a+cos(pi/2+4a) = sin(2.5a+1.5a)-sin4a = sin4a-sin4a = 0$