تابع ‎atanh()‎‎ در PHP

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