Trigonometric Function Values

The calculator evaluates four trigonometric functions for a given angle: sine, cosine, tangent and cotangent. You can enter the angle in degrees or radians ($180°=\pi$ rad).

The tangent is $\tan\alpha=\dfrac{\sin\alpha}{\cos\alpha}$ and is undefined when $\cos\alpha=0$ (at $90°, 270°\dots$). The cotangent $\cot\alpha=\dfrac{\cos\alpha}{\sin\alpha}$ is undefined when $\sin\alpha=0$ (at $0°, 180°\dots$).

It is worth remembering the values for special angles: $\sin30°=\tfrac12$, $\cos60°=\tfrac12$, $\sin45°=\cos45°=\tfrac{\sqrt2}{2}$, as well as the Pythagorean identity $\sin^2\alpha+\cos^2\alpha=1$.