## ACOS Inverse Trigonometric Arccosine Function

Section: Mathematical Functions

### Usage

Computes the`acos`

function for its argument. The general
syntax for its use is
y = acos(x)

where `x`

is an `n`

-dimensional array of numerical type.
Integer types are promoted to the `double`

type prior to
calculation of the `acos`

function. Output `y`

is of the
same size and type as the input `x`

, (unless `x`

is an
integer, in which case `y`

is a `double`

type).

### Function Internals

Mathematically, the`acos`

function is defined for all
arguments `x`

as

For real valued variables `x`

in the range `[-1,1]`

, the function is
computed directly using the standard C library's numerical `acos`

function. For both real and complex arguments `x`

, note that generally

### Example

The following code demonstates the`acos`

function over the range
`[-1,1]`

.
--> t = linspace(-1,1); --> plot(t,acos(t))