Signs of Trigonometry Functions in Quadrants

By Mary Jane Sterling

Part of Trigonometry For Dummies Cheat Sheet

An angle is in standard position when its vertex is at the origin, its initial side is on the positive x-axis, and the terminal side rotates counterclockwise from the initial side. The position of the terminal side determines the sign of the various trig functions of that angle. The following shows you which functions are positive — and you can assume that the other functions are negative in that quadrant.