Quick self-quiz

Tap each word to check what it stands for.

When to use it

Use it when evaluating trig functions for angles outside the first quadrant to determine whether the result is positive or negative.

Example

At 210°210° (Quadrant III), only tangent is positive, so sin⁡(210°)=−0.5\sin(210°) = -0.5 and cos⁡(210°)=−32\cos(210°) = -\frac{\sqrt{3}}{2}.

Common mistake

Thinking all functions are positive in every quadrant. Only the functions named by each letter are positive in that quadrant.