acosh

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

acosh — Inverse hyperbolic cosine

Description

acosh(float $num): float

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

Parameters

num: The value to process

Return Values

The inverse hyperbolic cosine of num

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User Contributed Notes 1 note

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rahmatjon at gmail dot com ¶

3 years ago

Hello!
There is no any example for acosh() function. Please put this one below the acosh() function's description.
Thank you!

Example:
<?php
    $x = 1;
    $y1 = acosh($x);
    echo "PHP function acosh(). acosh(" . $x . ") = " . $y1 . ".<br/>";
    $y2 = log($x + sqrt($x*$x -1));
    echo "By definition of acosh. acosh(" . $x . ") = " . $y2 . ".<br/>";

    $x = 10;
    $y1 = acosh($x);
    echo "PHP function acosh(). acosh(" . $x . ") = " . $y1 . ".<br/>";
    $y2 = log($x + sqrt($x*$x -1));
    echo "By definition of acosh. acosh(" . $x . ") = " . $y2 . ".<br/>";
?>