sqrt() Function Example in C Programming

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

sqrt() Function Overview

The sqrt() function in C computes the square root of a given number. It's an essential function in various mathematical, engineering, and scientific computations. The function is available in the math.h library. 

Key Points: 

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

- The function is designed to find the non-negative square root of a number. 

- If the provided argument is negative, the function will return a domain error. 

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

Source Code Example

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

int main() {
    double value, result;

    // Ask for user input
    printf("Enter a non-negative value to compute its square root: ");
    scanf("%lf", &value);

    if(value < 0) {
        printf("Error: Input should be non-negative.\n");
        return 1;

    // Compute the square root of the given value
    result = sqrt(value);

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

    return 0;


Enter a non-negative value to compute its square root: 4
Square root of 4.00 is: 2.00


1. We initiate by including the required header files: stdio.h for basic input/output operations and math.h for the sqrt() function.

2. In the main() function, we prompt the user to input a value.

3. A condition checks if the entered value is non-negative. If not, an error message is shown, and the program terminates.

4. If a non-negative value is provided, the sqrt() function calculates its square root.

5. The computed result is then displayed on the console.