Trigonometric Identities

This unit moves beyond basic geometry into the algebraic manipulation of trigonometric expressions and the proof of fundamental identities. Students master the reciprocal functions—secant, cosecant, and cotangent—and learn to use Pythagorean and complementary angle identities to simplify complex expressions. These skills are then applied to solving linear and quadratic trigonometric equations over specific domains, developing the rigorous proof-based reasoning required for higher-level mathematics.