Simplify a rational trigonometric expression by factoring out the GCF

The video tutorial focuses on simplifying trigonometric expressions by factoring both the numerator and denominator. It highlights the importance of identifying common factors and warns against common mistakes, such as incorrectly canceling terms. An example is provided to illustrate the correct approach to simplification.

What is the simplified version of the expression discussed in the text?

Explain the importance of being careful when simplifying fractions as mentioned in the text.