Simplifying Trig Expressions By Factoring ex 5

The video tutorial explains how to use substitution to simplify an expression by letting U equal the cotangent of X. It then demonstrates rewriting the expression in terms of U, factoring it by ensuring all terms are positive, and finally replacing U with the cotangent of X to achieve the final factored form.

Explain why both terms must be positive if the middle term is positive.

What is the final factored form after replacing U with cotangent of X?