Cosine Calculator
Find the cosine of an angle in degrees or radians.
Formula
cos θ = x-coordinate on the unit circle.
Cosine (approx.) ≈ cos((60)×pi÷180)
How to use
- Enter the angle.
- Choose degrees or radians.
- Read its cosine.
Examples
- cos 60° = 0.5.
Frequently asked questions
Does the result have a unit?
No. Cosine is a ratio and has no unit.
Can the angle be negative?
Yes. Cosine is even: cos(−θ) = cos θ.
Why might a special angle be approximate?
Angle conversion and trigonometry use floating-point arithmetic.
Sources
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