Cotangent (cot) is a trigonometric function defined as cot(x) = cos(x) / sin(x), or equivalently 1 / tan(x). It is the reciprocal of the tangent function.

When is cotangent undefined?

Cotangent is undefined wherever sin(x) = 0, i.e. at x = 0°, 180°, 360°, etc. (multiples of π radians). The calculator detects these values and displays an "Undefined" message.

cot(45°) = 1 because sin(45°) = cos(45°) = √2/2, so cos/sin = 1.

What is the range of cotangent?

Cotangent can take any real value from −∞ to +∞ (excluding the undefined points). Its period is 180° (or π radians).

How do I convert degrees to radians?

Multiply degrees by π/180. For example, 90° × (π/180) = π/2 ≈ 1.5708 radians. This calculator shows both representations automatically.

Is this the same as 1/tan(x)?

Yes. cot(x) = 1/tan(x) = cos(x)/sin(x). All three forms are mathematically equivalent wherever they are defined.

Cotangent Calculator

Enter an angle in degrees or radians and instantly get the cotangent value with a full breakdown.

Angle Input

Angle (degrees)

Common angles

Result

cot(x)

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Summary

The Cotangent Calculator computes cot(x) = cos(x) / sin(x) for any angle you enter. Choose degrees or radians, type your angle, and get the result plus the equivalent representation in the other unit. Handles edge cases like 0° and 180° where cotangent is undefined.

How it works

Select your input unit — degrees or radians.
Type the angle value into the input field.
The calculator converts to the other unit automatically.
cot(x) is computed as cos(x) / sin(x).
Results update live as you type; undefined values are flagged clearly.

Use cases

Verify trigonometry homework answers instantly.
Convert between cotangent values in degrees and radians.
Understand right-triangle relationships in geometry.
Check cotangent values while studying calculus or physics.
Quickly find cot of common angles like 30°, 45°, 60°, 90°.
Confirm results from a scientific calculator or CAS.

Frequently Asked Questions

Last updated: 2026-05-29 · Reviewed by Nham Vu

Angle (degrees)	—
Angle (radians)	—
sin(x)	—
cos(x)	—
cot(x) = cos/sin	—