# Arccos Calculator The Arccos(x) (inverse cosine) calculator is a tool that helps you find the angle in radians or degrees whose cosine is equal to a given value. It allows you to determine the angle measurement when you know the cosine of that angle.

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## Arccos definition

The Arccosine function is the inverse function of cos(x).

arccos(x) = cos-1(x)

For example, If the cosine of 60° is 0.5:

cos(60°) = 0.5

Then the arccos of 0.5 is 60°:

arccos(0.5) = cos-1(0.5) = 60°

## Arccos table

x arccos(x)
-1 180° π
-0.8660254 150° 5π/6
-0.7071068 135° 3π/4
-0.5 120° 2π/3
0 90° π/2
0.5 60° π/3
0.7071068 45° π/4
0.8660254 30° π/6
1 0

## Arccos Calculator Example

Angle (θ) Arccos(θ)
0 90°
0.5 60°
-0.5 120°
1
-1 180°

The arccos function (also known as inverse cosine function) returns the angle whose cosine is equal to a given value. It is commonly denoted as arccos(θ) or cos^(-1)(θ).

In this table, we have selected different values for θ and calculated their corresponding arccos(θ) values.

For example, when θ is 0, the arccos(0) is 90°. This means that the cosine of 90° is equal to 0.

Similarly, when θ is 0.5, the arccos(0.5) is 60°. This means that the cosine of 60° is equal to 0.5.

When θ is -0.5, the arccos(-0.5) is 120°. This means that the cosine of 120° is equal to -0.5.

When θ is 1, the arccos(1) is 0°. This means that the cosine of 0° is equal to 1.

When θ is -1, the arccos(-1) is 180°. This means that the cosine of 180° is equal to -1.

Please note that the angles in this table are given in degrees, and the values can be converted to radians if needed by multiplying by π/180.