#       
#  Overview
The **`acosh()` function** is used to return the inverse hyperbolic  cosine in radians of the argument `x` passed to it.

>Note: The arc hyperbolic cosine is the same as the *inverse hyperbolic cosine*.

Mathematically, this function is given by:

 acosh(x) = $acosh^{-1}$x 


# 
#  Syntax
```
double acosh(double x);
float  acosh(float x);
long double acosh(long double x);
```

# 
## Parameters
This function takes `x` as the only and mandatory parameter value.

 The value of this parameter must be equal to or greater than `1`. When the value passed is less than `1`, a domain error is returned.

##
## Return value
The returned value is the arc hyperbolic cosine of the argument `x`.
##
## Example


#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    // creating variables
	int x = 10;
	double result;
  
   // implementing the acosh
	result = acosh(x);
	cout << "acosh(10) = " << result << " radian" << endl;
	return 0;
}

# 
## Explanation 
* Line 8 and 9: We create the variables `x` and `result`.

* Line 12: We implement the `acosh()` function on the value of `x` and assign it to the variable `result`.

* Line 13: We print the result `variable`.

What is the acosh() function in C++?

 Returns the inverse hyperbolic cosine of a value in radians; only valid for inputs ≥ 1.