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Arccos Calculator

Find inverse cosine angle in degrees and radians

Input Value

Arccos Formula

θ = arccos(x), where cos(θ) = x

Arccos reverses the cosine function on its principal range. It converts a cosine value into the angle whose cosine equals that value.

Input must be between -1 and 1. The calculator returns the principal angle from 0° to 180°.

How Arccos Works

If cos θ equals x, arccos(x) returns the principal angle θ. The result is useful when a ratio or dot product is known first.

Inverse Cosine

Arccos reverses cosine.

Input Range

x must be from -1 to 1.

Output Range

Principal angle is 0° to 180°.

Angle Units

Result is shown in degrees and radians.

💡 Example: arccos(0.5)=60°=1.047198 rad.

Applications of Arccos

VectorsTrianglesDot ProductsPhysics

Frequently Asked Questions

What is an arccos calculator?
It finds the angle whose cosine equals the input value.
What is the arccos input range?
The input must be between -1 and 1 because cosine values stay in that range.
How do I use this calculator?
Enter a value from -1 to 1 and click Calculate.
What is the output range of arccos?
The principal output is from 0° to 180°, or 0 to π radians.
Where is arccos used?
Arccos is used in vectors, triangles, dot products, geometry, and physics.

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