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/>";
?>