(cosB/secB)-(cotB/tanB)=-cos^2B(cot^2B)

Can someone prove this by only working on one side. Show all steps please

We're not going to do your homework for you. But here's a hint: as ususal, the best way to approach this is to convert the tangent, cotangent and secant functions to their sine and cosine equivalents. Then it's a simple matter of combining terms and looking for opportuinities to use fundamental identities such as sin^2B + cos^2B = 1.