In this C++ tutorial, you will learn how to compute square root of given number using sqrt() function of cmath, with syntax and examples.
C++ sqrt()
C++ sqrt() computes square root of given number (argument).
Syntax
The syntax of C++ sqrt() is
sqrt(x)
where
| Parameter | Description |
|---|---|
| x | A double, float, long double, or any integral type value. |
Returns
The return value depends on the type of value passed for parameter x.
The return value of sqrt(x) is
- double if x is double or integral type.
- float if x is float.
- long double if x is long double.
If x is negative, then sqrt() returns nan.
The synopsis of sqrt() function is
double sqrt(double x); float sqrt(float x); long double sqrt(long double x); double sqrt(T x); // for integral type argument values
sqrt() is a function of cmath library. Include cmath library at the start of program, if using sqrt() function.
Example
In this example, we read a value from user into variable x, and find its square root using sqrt() function.
C++ Program
#include <iostream>
#include<cmath>
using namespace std;
int main() {
double x;
cout << "Enter a number : ";
cin >> x;
double result = sqrt(x);
cout << "sqrt(" << x << ") : " << result << endl;
} Output
Enter a number : 9 sqrt(9) : 3 Program ended with exit code: 0
Enter a number : 2 sqrt(2) : 1.41421 Program ended with exit code: 0
Enter a number : -2 sqrt(-2) : nan Program ended with exit code: 0
Conclusion
In this C++ Tutorial, we learned the syntax of C++ sqrt(), and how to use this function to find the square root of given number, with the help of examples.