化简:[sin(π+3α)cos(-α+3π)sin(α-3π/2)cos(11π/2-α)]÷[cos(3α+9π/2)sin(-α-π)

问题描述:

化简:[sin(π+3α)cos(-α+3π)sin(α-3π/2)cos(11π/2-α)]÷[cos(3α+9π/2)sin(-α-π)

[sin(π+3 cos(-α+3π)sin(α-3π/2)cos(11π/2-α)]÷[cos(3α+9π/2)sin(-α-π)]=[-sin3α(-cosα) sin(α-3π/2+2π) cos(6π-(π/2+α))]÷[cos(3α+π/2)sin(-α-π+2π)]=[-sin3α(-cosα) sin(α+...