PHP atanh() Function

PHPServer Side ProgrammingProgramming

Definition and Usage

The atanh() function returns the inverse hyperbolic tangent ratio of given given parameter. In other words, the return value of atanh() is hyperbolic tangent of given parameter. A inverse hyperbolic tangent function is defined as .

atanh(x) = 0.5Xlog((1+x)/(1-x))

This function returns a float value .

atanh ( float $arg ) : float Parameters Sr.NoParameter & Description 1arg A floating point value whose inverse hyperbolic tangent is to be calculated Return Values PHP atanh() function returns inverse hyperbolic tangent ratio of given parameter. PHP Version This function is available in PHP versions 4.x, PHP 5.x as well as PHP 7.x. Example Live Demo Following example calculates atanh(pi/4) and returns which is also the result of formula definition − <?php$arg=M_PI_4;
$res=atanh($arg);
echo "atanh(pi) = " . $res . "\n";$val = 0.5*log((1+$arg)/(1-$arg));
echo "using formula = " . $val; ?> Output This will produce following result − atanh(pi) = 1.0593061708232 using formula = 1.0593061708232 Example Live Demo Following example computes atanh(Π/10) − <?php$arg=M_PI/10;;
$val=atanh($arg);
echo "atanh(" . $arg . ") = " .$val;
?>

Output

This will produce following result −

atanh(0.31415926535898) = 0.32515348134414

Example

Live Demo

Let's check find out atanh(0). It returns 0 −

<?php
$arg=0;$val=atanh($arg); echo "atanh(" .$arg . ") = " . $val; ?> Output This will produce following result − atanh(0) = 0 Example Live Demo For parameter = 1 atanh() function returns INF <?php$arg=1;
$val=atanh($arg);
echo "atanh(" . $arg . ") = " .$val;
?>

Output

This will produce following result −

atanh(1) = INF