float cosh ( float $arg );

<?php
  n=4;
  echo "Your number is:".n;
  echo "<br>"."By using 'tanh()' function your value is:".tanh($n)."<br>";
?>

Your number is:4
By using 'tanh()' function your value is:0.99932929973907

<?php
  n=(-4);
  echo "Your number is:".n;
  echo "<br>"."By using 'tanh()' function your value is:".tanh($n)."<br>";
?>

Your number is:-4
By using 'tanh()' function your value is:-0.99932929973907

<?php
  n=(0.50);
  echo "Your number is:".n;
  echo "<br>"."By using 'tanh()' function your value is:".tanh($n)."<br>";
?>

Your number is:0.5
By using 'tanh()' function your value is:0.46211715726001

<?php
  n=(-0.50);
  echo "Your number is:".n;
  echo "<br>"."By using 'tanh()' function your value is:".tanh($n)."<br>";
?>

Your number is:-0.5
By using 'tanh()' function your value is:-0.46211715726001

<?php
  n=(M_PI_4);
  echo "Your number is: M_PI_4";
  echo "<br>"."By using 'tanh()' function your value is:".tanh(n)."<br>";
?>

Your number is: M_PI_4
By using 'tanh()' function your value is:0.65579420263267