### Home > PC > Chapter 4 > Lesson 4.3.1 > Problem 4-125

4-125.

Simplify the following trig expressions. Homework Help ✎

cos

*A*+ tan*A*sin*A*sin

^{2}*θ*+ tan^{2}*θ*− cot^{2}*θ*+ cos^{2}*θ*− sec^{2}*θ*+ csc^{2}*θ*

1. Change all terms to sine and cosine.

2. Get a common denominator.

3. Use the Fundamental Pythagorean Identity.

4. Simplify.

Use the Pythagorean Identities.

Change their forms to get 1s.

cos^{2}*θ* + sin^{2}*θ* = 1

1 + tan^{2}*θ* = sec^{2}*θ*

1 + cot^{2}*θ* = csc^{2}*θ*