 # C++ sqrt()

In this tutorial, we will learn about the sqrt() function in C++ with the help of examples.

The `sqrt()` function in C++ returns the square root of a number. This function is defined in the cmath header file.

Mathematically, `sqrt(x) = √x`.

### Example

``````#include <iostream>
#include <cmath>
using namespace std;

int main() {
cout << "Square root of 25 = ";

// print the square root of 25
cout << sqrt(25);

return 0;
}

// Output: Square root of 25 = 5``````

## sqrt() Syntax

The syntax of the `sqrt()` function is:

``sqrt(double num);``

## sqrt() Parameters

The `sqrt()` function takes the following parameter:

• num - a non-negative number whose square root is to be computed

Note: If a negative argument is passed to `sqrt()`, domain error occurs.

## sqrt() Return Value

The `sqrt()` function returns:

• the square root of the given argument

## sqrt() Prototypes

The prototypes of `sqrt()` as defined in the cmath header file are are:

``````double sqrt(double x);

float sqrt(float x);

long double sqrt(long double x);

// for integral type
double sqrt(T x);``````

## Example 1: C++ sqrt()

``````#include <iostream>
#include <cmath>
using namespace std;

int main() {
double num = 10.25;

double result = sqrt(num);

cout << "Square root of " << num << " is " << result;

return 0;
}``````

Output

`Square root of 10.25 is 3.20156`

## Example 2: sqrt() function With integral Argument

``````#include <iostream>
#include <cmath>
using namespace std;

int main() {
long num = 464453422;

double result = sqrt(num);

cout << "Square root of " << num << " is " << result;

return 0;
}``````

Output

`Square root of 464453422 is 21551.2`