# Precalculus : Prove Trigonometric Identities

## Example Questions

### Example Question #1 : Prove Trigonometric Identities

Simplify:

Explanation:

To simplify , find the common denominator and multiply the numerator accordingly.

The numerator is an identity.

Substitute the identity and simplify.

### Example Question #2 : Prove Trigonometric Identities

Evaluate in terms of sines and cosines:

Explanation:

Convert  into its sines and cosines.

### Example Question #3 : Prove Trigonometric Identities

Simplify the following:

Explanation:

First factor out sine x.

Notice that a Pythagorean Identity is present.

The identity needed for this problem is:

Using this identity the equation becomes,

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