 # C++ exp2()

The exp2() function in C++ returns the base-2 exponential function, i.e. 2 raised to the given argument.

The function is defined in <cmath> header file.

`[Mathematics] 2x = exp2(x) [C++ Programming]`

## exp2() prototype [As of C++ 11 standard]

```double exp2(double x);
float exp2(float x);
long double exp2(long double x);
double exp2(T x); // For integral type```

## exp2() Parameters

The exp2() function takes a single mandatory argument (can be positive, negative or 0).

## exp2() Return value

The exp2() function returns the value in the range of [0, ∞].

If the magnitude of the result is too large to be represented by a value of the return type, the function returns `HUGE_VAL` with the proper sign, and an overflow range error occurs.

## Example 1: How exp2() function works in C++?

``````#include <iostream>
#include <cmath>

using namespace std;

int main()
{
double x = -6.19, result;

result = exp2(x);
cout << "exp2(x) = " << result << endl;

return 0;
}```
```

When you run the program, the output will be:

```exp2(x) = 0.013697
```

## Example 2: exp2() function with integral type

``````#include <iostream>
#include <cmath>

using namespace std;

int main()
{
long int x = 14;
double result;

result = exp2(x);
cout << "exp2(x) = " << result << endl;

return 0;
}``````

When you run the program, the output will be:

```exp2(x) = 16384
```