sinx + cosx = √2sin5x; (sinx/2 + cosx/2 )^2 + √3 cosx = 2; 2sin^2x + √3 sin2x = 3

a) sinx + cosx = √2sin5x
b) (sinx/2 + cosx/2 )^2 + √3 cosx = 2
c) 2sin^2x + √3 sin2x = 3