# acosd

Inverse cosine in degrees

## Syntax

``Y = acosd(X)``

## Description

example

````Y = acosd(X)` returns the inverse cosine (cos-1) of the elements of `X` in degrees. The function accepts both real and complex inputs. For real values of `X` in the interval [-1, 1], `acosd(X)` returns values in the interval [0, 180].For values of `X` outside the interval [-1, 1] and for complex values of `X`, `acosd(X)` returns complex values. ```

## Examples

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Verify that inverse cosine of 0 is exactly 90.

`acosd(0)`
```ans = 90 ```

Show that the inverse cosine, followed by cosine, returns the original values of `X`.

`cosd(acosd([2 3]))`
```ans = 1×2 2 3 ```

`acosd([2 3])` returns two complex angles, which are then passed to the `cosd` function. `cosd` returns the original values, `2` and `3`.

## Input Arguments

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Cosine of angle, specified as a real-valued or complex-valued scalar, vector, matrix, multidimensional array, table, or timetable. The `acosd` operation is element-wise when `X` is non-scalar.

Data Types: `single` | `double` | `table` | `timetable`
Complex Number Support: Yes

## Output Arguments

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Angle in degrees, returned as a real-valued or complex-valued scalar, vector, matrix, multidimensional array, table, or timetable of the same size as `X`.

## Version History

Introduced before R2006a

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