PHP atanh() Function – Inverse Hyperbolic Tangent

atanh() returns the inverse hyperbolic tangent of a given float argument.

Signature: float atanh(float $arg) Parameter: $arg – the value to be processed.

Return value: The inverse hyperbolic tangent of $arg.

Example:

<?php
echo atanh(M_PI_4)."<br>";
echo atanh(0.50)."<br>";
echo atanh(-0.50)."<br>";
echo atanh(1)."<br>";
echo atanh(-1)."<br>";
?>

Output:

1.0593061708232
0.54930614433405
-0.54930614433405
INF
-INF