[lacol]

trigonometric identies

Prove the identity cot^2x - cos^2x = cos^2x -cot^2x

[ebaines]

In general the statement as you wrote it is not true. I suspect what you meant to write is this:



As usual for these types of problems, first step is to convert the cotangent function into its sine and cosine equivalent, then look for opportunities to apply common identities such as . Try it and post back with your attempt to complete the proof, and we'll be happy to check it for you.