Presentation on theme: "Using Fundamental Identities"— Presentation transcript:
1 Using Fundamental Identities Objectives:Recognize and write the fundamental trigonometric identitiesUse the fundamental trigonometric identities to evaluate trigonometric functions, simplify trigonometric expressions, and rewrite trigonometric expressions
2 WHY???Fundamental trigonometric identities can be used to simplify trigonometric expressions, such as for the coefficient of friction.
3 Fundamental Trigonometric Identities Reciprocal IdentitiesQuotient Identities
4 Fundamental Trigonometric Identities Pythagorean IdentitiesEven/Odd Identities
5 Fundamental Trigonometric Identities Cofunction Identities
6 Example: If and Ө is in quadrant II, find each function value. a) sec ӨTo find the value of this function, look for an identity that relates tangent and secant.Tip: Use Pythagorean Identities.
7 Example: If and Ө is in quadrant II, find each function value. (Cont.) b) sin Өc) cot (- Ө )Tip: Use Quotient Identities.Tip: Use Reciprocal and Negative-Angle Identities.
8 2. Use the valuescos x > 0 and identities to find the values of all six trigonometric functions.What quadrant will you use?1st quadrant