Both work. Degrees are the school default; switch to radians for calculus-style problems. The calculator converts before evaluating.

Why is tan 90° undefined?

Because tan = sin/cos, and cos 90° = 0. Division by zero is undefined, so tan 90° has no value.

Can it solve trig equations?

For equations like sin(x) = 1/2, use the equation solver, which returns every solution. This calculator evaluates a single function value.

Trigonometry Calculator

Evaluate any trigonometric function instantly. Enter an angle to get sin, cos, tan, cot, sec or csc, or enter a value to get the inverse. Special angles like 30°, 45° and 60° also show their exact values.

How to use the trigonometry calculator

Choose the function.
Enter the angle (degrees or radians) or the value for an inverse function.
Read the decimal answer and, for special angles, the exact value.

Examples

sin 30°

Answer: 0.5

tan 45°

Answer: 1

arcsin(0.5)

Answer: 30°