Cotangent Calculator
Calculate cot(θ) from a signed degree angle. Multiples of 180° are undefined; 90° and 270° have cotangent zero.
Formula
cot(θ) = cos(θ)/sin(θ); use θπ/180 radians. Undefined at θ = 180k°, k integer.
Cotangent (unitless) ≈ cos(((45)-360×round((45)÷360))×pi÷180)÷(sin(((45)-360×round((45)÷360))×pi÷180)×min(1,ceil(abs((45)-180×round((45)÷180)))))
How to use
- Enter an angle from −360,000° to 360,000°.
- Use degrees, including a minus sign if needed.
- Read the unitless cotangent or the undefined-angle error.
Examples
- cot(45°) = 1; cot(135°) = −1; cot(90°) = 0.
Frequently asked questions
What happens at multiples of 180°?
They are rejected before a finite result can be reported.
Why does 90° give zero?
Cosine is zero and sine is one. Cotangent is defined even though tangent is not.
Is cotangent the inverse tangent?
No. Arctangent returns an angle; cotangent is the cosine-to-sine ratio.
Sources
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