Rút gọn: A= sin5x - 2sinx(cos4x + cos2x); B = cos^2x + cos^2(x + π/3); C = cos^3x.sinx - sin^3x.cosx; D = tan(5π/4 - x)(1 + sin2x)

Rút gọn:
a) A= sin5x - 2sinx(cos4x + cos2x)
b) B = cos^2x + cos^2(x + π/3)
c) C = cos^3x.sinx - sin^3x.cosx
d) D = tan(5π/4 - x)(1 + sin2x)
e) E = sin^3x(1 + cotx) + cos^3x(1 + tanx)