化简sin(α-2π)cos(3π/2-α)+tan(π-α)tan(π/2+α)+cos^2(π-α)

问题描述:

化简sin(α-2π)cos(3π/2-α)+tan(π-α)tan(π/2+α)+cos^2(π-α)

sin(α-2π)cos(3π/2-α)+tan(π-α)tan(π/2+α)+cos^2(π-α)
=-sinasina+tanacota+cos^2a
=cos^2a-sin^2a+1
=2cos^2(a)