# Documentation

### This is machine translation

Translated by
Mouse over text to see original. Click the button below to return to the English verison of the page.

# acosd

Inverse cosine in degrees

## Description

example

Y = acosd(X) returns the inverse cosine (cos-1) of the elements of X in degrees. The function's domain and range include complex values. For real elements of X in the domain [-1,1], acosd returns values in the range [0, 180]. For values of X outside this range, acosd returns complex values.

## Examples

collapse all

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 =

2.0000    3.0000

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

collapse all

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

Data Types: single | double
Complex Number Support: Yes

## Output Arguments

collapse all

Angle in degrees, returned as a real-valued or complex-valued scalar, vector, matrix, or N-D array of the same size as X.

collapse all

### Tall Array Support

This function fully supports tall arrays. For more information, see Tall Arrays.