f(x)=(2cos^2 a/2-sina-1)/(sin(a+π/3)sin(a-π/3)

问题描述:

f(x)=(2cos^2 a/2-sina-1)/(sin(a+π/3)sin(a-π/3)

f(x)=(2cos^2 a/2-sina-1)/(sin(a+π/3)sin(a-π/3)
=4(cosa-sina)/(sin^2a-3cos^2a) 求啥?