RETURNS the inverse hyperbolic tangent of an argument given in radians.
This function obtains the angle values from the corresponding hyperbolic tangent.
Compatible with LOCALE only, up to PHP 7.4.XX.
<?php
float atanh ( float $num )
where,
$num = The argument to process in radians
?>
EXERCISE
<table width="100%" border="1" cellspacing="5" cellpadding="5">
<tr><td colspan="4">atanh($num)</td></tr>
<tr><td>DEGREES ( ° )<td>RADIANS ( rd )</td><td>OPERATION</td><td>RESULT</td></tr>
<?php
// setlocale(LC_ALL, 'de_DE', 'de-DE');
$pi = M_PI;
$pi_arr01 = [ '0' => 0, 'Л/4' => $pi/4,
'Л/2' => $pi/2, '3Л/4' => 3*$pi/4, 'Л' => $pi, '5Л/4' => 5*$pi/4,
'3Л/2' => 3*$pi/2, '7Л/4' => 7*$pi/4, '2Л' => 2*$pi ];
foreach($pi_arr01 as $val_a => $val_n)
{
echo '<td>' . rad2deg($val_n) . '</td>';
echo '<td>' . $val_a . '</td>';
echo '<td>atanh( ' . tanh($val_n) . ' )</td>';
echo '<td>' . atanh(tanh($val_n)) . '<br><br>' . rad2deg(atanh(tanh($val_n))) . '°' . '</td></tr>';
}
?>
<td colspan="4">ed48</td></tr></table>
EXERCISE
<table width="100%" border="1" cellspacing="5" cellpadding="5">
<tr><td colspan="5">tanh($num)/atanh($num)</td></tr>
<tr><td>DEGREES ( ° )<td>RADIANS ( rd )</td><td>OPERATION</td><td>tanh($num)</td><td>atanh($num)</td></tr>
<?php
setlocale(LC_ALL, 'de_DE', 'de-DE');
$pi = M_PI;
$pi_arr01 = [ '0' => 0, 'Л/4' => $pi/4,
'Л/2' => $pi/2, '3Л/4' => 3*$pi/4, 'Л' => $pi, '5Л/4' => 5*$pi/4,
'3Л/2' => 3*$pi/2, '7Л/4' => 7*$pi/4, '2Л' => 2*$pi ];
foreach($pi_arr01 as $val_a => $val_n)
{
echo '<td>' . rad2deg($val_n) . '</td>';
echo '<td>' . $val_a . '</td>';
echo '<td>tanh( ' . $val_n . ' )</td>';
echo '<td>' . tanh($val_n) . '</td>';
echo '<td>' . 1/2*(log(1 + tanh($val_n)) - log(1 - tanh($val_n))) . '</td></tr>';
}
?>
<td colspan="5">ed48</td></tr></table>