# Fortran Wiki acosh

## Description

acosh(x) computes the inverse hyperbolic cosine of x.

## Standard

Fortran 2008 and later

## Class

Elemental function

## Syntax

result = acosh(x)

## Arguments

• x - the type shall be real or complex.

## Return value

The return value has the same type and kind as x. If x is complex, the imaginary part of the result is in radians and lies between $0 \leq \mathop{Im}{\acosh(x)} \leq \pi$.

## Example

program test_acosh
real(8), dimension(3) :: x = (/ 1.0, 2.0, 3.0 /)
write (*,*) acosh(x)
end program