Unit Circle

Hover any point to see exact values · MAT 172 reference

MAT 172 — Pre-Calc Trig

Hover near any angle point to explore · All Students Take Calculus

Angle values

Angle
—
Radians
—
cos θ
—
sin θ
—
tan θ
—

Key identities

sin²θ + cos²θ = 1
tan θ = sin θ / cos θ
sin(−θ) = −sin θ
cos(−θ) = cos θ

Quadrant signs

Q IAll positive (0–90°)
Q IISin + only (90–180°)
Q IIITan + only (180–270°)
Q IVCos + only (270–360°)
All Students Take Calculus — which function is positive, starting Q I going counterclockwise.