1. 5.1- Verifying Identities

2. Ex. 1 Use the values and to find the values of all
six trigonometric functions.
Since tangent is positive and cosine is
negative, we must be in QIII

3. Ex. 2 Simplify:

4. When you are asked to “verify” or “prove” an identity, the idea is
to make one side look like the other.
Ex. 3 Verify:

5. Some strategies for verifying identities:
Work with the more complicated side first.
Change everything into sines/cosines.
Factor.
Combine fractions (using LCD).
Multiply the numerator and denominator by the same thing.
Work each side separately until they both match.

6. Ex. 4 Verify:

7. Ex. 5 Verify:

8. Ex. 6 Verify:
LCD =

10. Ex. 7 Rewrite so that it is not in fractional form: