Add two trig functions as fractions

The video tutorial explains how to express tangent and cotangent using sine and cosine. It then guides through finding a common denominator for these expressions, which is sine times cosine. The tutorial demonstrates multiplying both sides by appropriate terms to achieve this common denominator. Finally, it simplifies the expression using trigonometric identities, resulting in a final answer without fractions.

Explain the significance of sine squared plus cosine squared in trigonometry.

What identity is used to rewrite the expression in the final answer?