#     
## Overview
The **`logb()` function** in C++ is  used to return the logarithm of a given number (`|x|`) using the `FLT_RADIX` as the base of the logarithm.

> Note:`FLT_RADIX` is the value of the base of the logarithm. Generally, it is 2, so the `logb()` is equivalent to `log2()` for any positive number value.

The `logb()` function is defined in the `<cmath>` header file.
## Syntax
```
double logb (double x);
float logb (float x);
long double logb (long double x);
double logb (T x); // For integral type
```
## Parameter value
The `logb()` function takes a single parameter value:

 **`x`**: The number whose logarithm is computed.
## Return value
The `logb()` function returns the logarithm of the argument passed to it as its parameter value.


## Example 



#include <iostream>
#include <cmath>

using namespace std;

int main ()
{
	double x =100, result;

	result = logb(x);
	cout << "logb(" << x << ") = " << "log(|" << x << "|) = "<< result << endl;

	return 0;
}

## Explanation
* Line 8: We create variables `x` and `result`.
* Line 10: We use the `logb()` function on the `x` variable and assign the output to the other variable `result`.
* Line 11: We print the `result` variable.

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

Returns the logarithm of a given number using FLT_RADIX as the base; defined in <cmath>.