sin(θ -5π)/tan(3π-θ)*cot(π/2-θ)/tan(θ -3/2π)*cos(8π-θ)/sin(-θ-4π)化简

题目

sin(θ -5π)/tan(3π-θ)*cot(π/2-θ)/tan(θ -3/2π)*cos(8π-θ)/sin(-θ-4π)化简

答案

=sinθ /(-tanθ)*(-cotθ)/tanθ*cosθ/(-sinθ)
=-(cosθ)^2/sinθ