exp() Function Example in C Programming

In this source code example, we will see how to use the exp() function in C programming with an example.

exp() Function Overview

The exp() function in C calculates the exponential function of a given number. More specifically, it computes the value of \( e^x \), where e is the base of the natural logarithm, approximately equal to 2.71828. 

This function is foundational in numerous scientific, engineering, and financial applications. The function can be found within the math.h library. 

Key Points: 

- Make sure you include the math.h header to access the exp() function. 

- The input to this function can be any real number. 

- e (the base of the natural logarithm) raised to any power can be calculated using this function. 

- Always remember to link the math library using the -lm flag when compiling.

Source Code Example

#include <stdio.h>
#include <math.h>  // Necessary for exp()

int main() {
    double value, result;

    // Request a value from the user
    printf("Enter a value to compute its exponential: ");
    scanf("%lf", &value);

    // Calculate the exponential of the given value
    result = exp(value);

    // Display the computed result
    printf("Exponential of %.2lf is: %.2lf\n", value, result);

    return 0;


Enter a value to compute its exponential: 1
Exponential of 1.00 is: 2.72


1. First and foremost, we include the essential header files: stdio.h for basic I/O functionalities and math.h to employ the exp() function.

2. Within the main() function, we prompt the user to provide a value.

3. We then use the exp() function to determine the value of \( e^x \) where x is the user's input.

4. The final result is printed out on the console.