Inverse hyperbolic cosine

acos
asin
Math Functions
PHP Manual

# acosh

(PHP 4 >= 4.1.0, PHP 5)

acosh — Inverse hyperbolic cosine

### Description

float acosh ( float `$arg` )

Returns the inverse hyperbolic cosine of `arg`, i.e. the value whose hyperbolic cosine is `arg`.

### Parameters

`arg`

  The value to process

### Return Values

The inverse hyperbolic cosine of `arg`

### Changelog

Version | Description
--- | ---
5.3.0 | This function is now available on all platforms

### See Also

- cosh() - Hyperbolic cosine
- acos() - Arc cosine
- asinh() - Inverse hyperbolic sine
- atanh() - Inverse hyperbolic tangent

acos
asin
Math Functions
PHP Manual