Unit 7

Units 1 to 6 Review

Trigonometric Identities

An identity shows two expressions are equivalent, even though they look different, for any permissible value(s) of the variable.

Common trigonometric identities are the Pythagorean identities, reciprocal and quotient identities, double angle identities, and sum and difference identities.

Identities are used to simplify expressions and equations.

Trigonometric equations can be solved using identities.