7.6 Exploration: Trig Identities Honors Analysis Learning Target: I can develop trigonometric identities
Identity #1:
Identity #2:
Use the triangle below to prove the identity shown above. Hint: How can the hypotenuse be labeled using a and b?
Deriving the Pythagorean Identities:
Trig Identities Summary:
Simplify:
Strategies for simplifying trigonometric expressions Write trig functions in term of sin/cos/tan Look for Pythagorean identities (may need to factor out GCF to find) Fractions: Find a common denominator & combine Fractions: Break up a sum/difference in the numerator as two fractions with the same denominator
Verify the trig identity
Verify the trig identity:
Trig Identity Tips Make obvious replacements Convert reciprocal functions to sin/cos/tan where possible If factored, multiply out If not factored, factor out GCF Try converting all values to sin/cos form If there is a sum or difference in the numerator, split it up into two fractions (CAREFUL!! You can’t split up denom!) Sum/difference of fractions – find common denominator and add
Multiple Angle Identities
Simplify
Evaluate:
Ch. 7 Test Review: Identities
Simplify:
sin cot
Simplify: