The **`exp` function** is part of the `<math.h>` header file. It is equivalent to an exponent in mathematics. The function takes in a single parameter: a `double` value. It then raises it to the power of `e` and returns the resultant `double` value.


> exp(2) = $e^2$

The illustration below shows how `exp` works:

# Declaration

The `exp` function is defined as follows:

```C
double exp(double x);
```

It takes in a single parameter of type `double`.

# Example

The following code snippet shows how we can use the `exp` function. The code below outputs the exponent of the number in the parameter:


#include <stdio.h> // Including header file for printf function
#include <math.h> // Including header file for exp function

int main(){

  double num = 5.0; // assign value to number
  double result; // variable to store result
  result = exp(num); // taking exponent of number
  printf("The exponent of %.2lf is: %.2lf", num, result);
  return 0;
}

What is exp in C?

Calculates e raised to the power of a given double parameter using the exp function from <math.h> header.