Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Trigonometric functions relate angles in a right triangle to ratios of side lengths. The six main trigonometric functions are sine (sin), cosine (cos), tangent (tan), cosecant (csc), secant (sec), and cotangent (cot).
Related terms
Unit circle: A circle with radius 1 centered at the origin used to define trigonometric values for any angle.
Periodicity: The property of trigonometric functions that repeats their values after certain intervals.
Inverse trigonometric functions: Functions that "undo" the effects of trigonometric functions by finding angles given specific ratios.