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.

備注:此函數不適用於 Windows 平台。

See also: acos(), asinh(), and atanh().