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