#    
## Overview
In C++, the **`log()`** **function** is used to return the natural logarithm of the argument `x` that is passed to it.

Mathematically, the natural logarithm of a number is given by: 

Log(x) = Log
$Log_{10}$x

## Syntax
```
double log (double x);
float log (float x);
long double log (long double x);
```
## Parameter value 
The `log()` function takes a single parameter value `x`, which represents the number whose natural logarithm is to be computed. This parameter value must be between zero (`0`) and infinity(`∞`). 

Any value passed to the function that is less than zero (`0`)  will return `NaN`.


## Return value 
The `log()` function returns the natural logarithm of the argument `x` that is passed to it.

## Code example


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

int main ()
{
  // creating variables
  int x = 100;
	double result;
  
  // implementing the log() function
	result = log (x);
	cout << "log(100) = " << result << endl;
	
	return 0;
}

## Code explanation
* Lines 8–9: We create the variables `x` and `result`.
* Line 12: We implement the `log()` function on the value of the `x` variable and assign the output to the `result` variable.
* Line 13: We print the `result` variable.

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

Computes the natural logarithm of x, returning NaN for any x < 0. Syntax supports double, float, and long double.