PHP asinh( ) Function

In mathematics, the inverse hyperbolic functions are the inverse functions of the hyperbolic functions. For a given value of a hyperbolic function, the corresponding inverse hyperbolic function provides the corresponding hyperbolic angle. PHP provides us with builtin functions for inverse hyperbolic calculations. The asinh() function in PHP is used to find the inverse hyperbolic sine of a number passed to it as argument.
Syntax:  

float asinh($value)

Parameters: This function accepts a single parameter $value. It is the number whose inverse hyperbolic sine value you want to find. The value of this parameter must be in radians.
Return Value: It returns a floating point number which is the inverse hyperbolic sine value of a number passed to it as argument.
Examples: 

Input : asinh(7)
Output : 2.6441207610586

Input : asinh(56)
Output : 4.7185785811518

Input : asinh(2.45)
Output : 1.6284998192842

Below programs, taking different values of $value are used to illustrate the asinh() function in PHP: 

• Passing 7 as a parameter:

• Output: 

2.6441207610586

• Passing 56 as a parameter:

• Output: 

4.7185785811518

• Passing 2.45 as a parameter:

• Output: 

1.6284998192842

Reference: 
http://php.net/manual/en/function.asinh.php