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Cotangent Calculator (cot)

Calculate the cotangent of any angle in degrees or radians. Identifies undefined points, exact values for special angles, and reciprocal trig.

cot(45°)
1
Exact: 1
Deduction Steps:
Input: cot(45°)
Equivalent: 45° = 0.7854 rad
cot(θ) = cos(θ) / sin(θ) = 1 / tan(θ) = 0.7071 / 0.7071 = 1
Exact Value: 1
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What Is a Cotangent Calculator (cot)?

Cotangent is the reciprocal trigonometric function of tangent. In a right triangle, cot(θ) is the ratio of the adjacent leg to the opposite leg: cot(θ) = Adjacent / Opposite = cos(θ) / sin(θ) = 1 / tan(θ).

How to Use This Calculator

  1. Enter angle θ and select Degrees or Radians.
  2. View the calculated cotangent value or vertical asymptote alert.
  3. Review the exact mathematical derivation.

Cotangent Trigonometric Definition

\cot(\theta) = \frac{\text{Adjacent}}{\text{Opposite}} = \frac{1}{\tan(\theta)} = \frac{\cos(\theta)}{\sin(\theta)}

Cotangent is undefined whenever sin(θ) = 0, which occurs at integer multiples of 180° (0°, ±180°, ±360°, etc.).

Worked Example

Scenario: Calculate cot(30°)

Given: θ = 30°

cos(30°) = √3 / 2, sin(30°) = 1 / 2

cot(30°) = cos(30°) / sin(30°) = (√3/2) / (1/2) = √3 ≈ 1.732051

Result: cot(30°) = √3 ≈ 1.7321

Tips & Key Notes

  • Cotangent is undefined at 0°, 180°, 360° because sin(θ) = 0 at those angles.
  • Like tangent, cotangent has a period of 180° (or π radians).
  • At 45°, tan(45°) = 1 and cot(45°) = 1.

Frequently Asked Questions

Why is cot(0°) undefined?

At 0°, sin(0°) = 0. Because cot(θ) = cos(θ) / sin(θ), evaluating cot(0°) requires dividing by zero (1 / 0), which is undefined.

What is the relationship between tan and cot?

They are reciprocals: cot(θ) = 1 / tan(θ) and tan(θ) = 1 / cot(θ). They are also cofunctions: cot(θ) = tan(90° - θ).

What are common exact values of cotangent?

cot(30°) = √3, cot(45°) = 1, cot(60°) = √3/3 ≈ 0.577, cot(90°) = 0.

What is the domain and range of cotangent?

Domain: all real numbers except θ = kπ (k integer). Range: all real numbers (-∞, +∞).

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