Cotangent Calculator (cot θ)

Calculate the cotangent of any angle in degrees or radians. Shows all 6 trig functions, quadrant visual, common values table, and identity reference.

cot(θ)
1.000000
cot(θ) = cos(θ)/sin(θ) = 1/tan(θ)
tan(θ)
1.000000
tan(θ) = sin(θ)/cos(θ)
sin(θ)
0.707107
Sine of the input angle
cos(θ)
0.707107
Cosine of the input angle
Quadrant
I
Angle: 45.00° (normalized to 0–360°)
Reference Angle
45.000000°
Acute angle formed with the nearest x-axis
cot(θ) Sign
Positive
Positive in Q1 & Q3, negative in Q2 & Q4
Period
180°
cot repeats every 180° (π radians)
sec(θ)
1.414214
sec(θ) = 1/cos(θ)
csc(θ)
1.414214
csc(θ) = 1/sin(θ)

Quadrant Indicator

II
cot:
I
cot: +
III
cot: +
IV
cot:

All Six Trig Functions

FunctionValueRelationship
sin(θ)0.707107Opposite / Hypotenuse
cos(θ)0.707107Adjacent / Hypotenuse
tan(θ)1.000000Opposite / Adjacent = sin/cos
cot(θ)1.000000Adjacent / Opposite = cos/sin
sec(θ)1.4142141 / cos(θ)
csc(θ)1.4142141 / sin(θ)

Common Cotangent Values

AngleRadianscot(θ) Exactcot(θ) Decimal
0.0000Undefined
30°0.5236√3 ≈ 1.73211.7321
45°0.785411.0000
60°1.04721/√3 ≈ 0.57740.5774
90°1.570800.0000
120°2.0944−1/√3 ≈ −0.5774-0.5774
135°2.3562−1-1.0000
150°2.6180−√3 ≈ −1.7321-1.7321
180°3.1416Undefined
210°3.6652√3 ≈ 1.73211.7321
225°3.927011.0000
240°4.18881/√3 ≈ 0.57740.5774
270°4.712400.0000
300°5.2360−1/√3 ≈ −0.5774-0.5774
315°5.4978−1-1.0000
330°5.7596−√3 ≈ −1.7321-1.7321
360°6.2832Undefined
Cotangent Identities
IdentityFormula
Definitioncot(θ) = cos(θ) / sin(θ) = 1 / tan(θ)
Pythagorean1 + cot²(θ) = csc²(θ)
Double anglecot(2θ) = (cot²(θ) − 1) / (2·cot(θ))
Sum formulacot(A+B) = (cot(A)·cot(B) − 1) / (cot(A) + cot(B))
Cofunctioncot(θ) = tan(90° − θ)
Periodcot(θ + 180°) = cot(θ)
Negative anglecot(−θ) = −cot(θ) (odd function)
Planning notes, formulas, and examples

About the Cotangent Calculator (cot θ)

The **Cotangent Calculator** computes cot(θ) = cos(θ)/sin(θ) for any angle and simultaneously displays all six trigonometric function values, the quadrant, reference angle, and sign information. Enter an angle in degrees or radians, and the tool delivers instant, precise results with adjustable decimal precision.

Cotangent is one of the six fundamental trigonometric functions, defined as the ratio of the adjacent side to the opposite side in a right triangle, or equivalently as cos(θ)/sin(θ). It is the reciprocal of the tangent function and has a period of 180° (π radians), making it repeat twice as often as sine and cosine. Cotangent is undefined wherever sin(θ) = 0 — that is, at 0°, 180°, 360°, and so on.

This calculator offers much more than a simple cot evaluation. It shows all six trig functions side by side with their triangle relationships, highlights the current quadrant with a color-coded visual grid (showing whether cot is positive or negative in each quadrant), and provides a comprehensive common-values table covering 17 standard angles from 0° through 360°. A collapsible identities reference lists the definition, Pythagorean identity, double-angle formula, sum formula, cofunction relationship, and symmetry property.

Eight preset buttons cover the most commonly needed angles (30°, 45°, 60°, 90°, 120°, and their radian equivalents), and a toggle lets you show or hide the reciprocal functions (sec and csc) to reduce clutter when you only need the primary values.

When This Page Helps

Cotangent Calculator (cot θ) helps you avoid repetitive setup mistakes when solving trigonometric and coordinate-geometry problems. Instead of recalculating conversions, signs, and edge cases by hand, you can test inputs immediately, inspect intermediate values, and confirm final answers before submitting work or using numbers in downstream calculations. It surfaces key outputs like cot(θ), tan(θ), sin(θ) in one pass.

How to Use the Inputs

  1. Enter the required inputs (Angle (θ), Angle Unit, Decimal Precision).
  2. Complete the remaining fields such as Show Reciprocal Functions.
  3. Review the output cards, especially cot(θ), tan(θ), sin(θ), cos(θ).
  4. Compare the result with the formula, diagram, or example values to catch sign, unit, or rounding mistakes.
Formula used
cot(θ) = cos(θ)/sin(θ) = 1/tan(θ). Undefined when sin(θ) = 0 (at 0°, 180°, 360°, …). Period: 180° (π radians). Pythagorean identity: 1 + cot²(θ) = csc²(θ). Cofunction: cot(θ) = tan(90° − θ).

Example Calculation

Result: 1

Using θ=45°, the calculator returns 1. This example mirrors the calculator's live computation flow and is useful for checking manual steps and unit handling.

Tips & Best Practices

  • Cotangent is undefined at 0°, 180°, and 360° because sin(θ) = 0 at those angles.
  • cot is positive in Quadrants I and III, negative in Quadrants II and IV.
  • cot(θ) = tan(90° − θ) — cotangent and tangent are cofunctions.
  • The period of cot is 180° (π), half that of sin and cos.
  • For very small angles, cot(θ) ≈ 1/θ (in radians), so it approaches infinity as θ → 0.

What This Cotangent Calculator (cot θ) Solves

This calculator is tailored to cotangent calculator (cot θ) workflows, including common input modes, unit handling, and special-case behavior. It is designed for fast checking during homework, exam preparation, technical drafting, and coding tasks where trigonometric consistency matters.

How To Interpret The Outputs

Use the primary result together with supporting outputs to verify direction, magnitude, and validity. Cross-check against known identities or geometric constraints, and confirm that angle ranges, sign conventions, and domain restrictions are satisfied before using the numbers elsewhere.

Study And Practice Strategy

A reliable way to improve is to solve once manually, then verify with the calculator and explain any mismatch. Repeat this on varied examples and edge cases. The built-in preset scenarios for quick trials, comparison tables for side-by-side validation, visual cues that make trends and quadrants easier to read help you build pattern recognition and reduce sign or conversion errors over time.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • Cotangent (cot) is a trigonometric function defined as the ratio cos(θ)/sin(θ), or equivalently the reciprocal of tangent: cot(θ) = 1/tan(θ). In a right triangle, it equals the adjacent side divided by the opposite side.