1-csc (x) sin^3 (x)=cos^2 Any idea?

This is an identity.

LHS

1 - csc(x)*sin³(x) → 1 - sin³(x)/sin(x) → 1- sin²(x) → cos²(x)

.

I answered this one here......http://web2.0calc.com/questions/1-csc-x-sin-3-x-cos-2