# Java.lang.StrictMath.sqrt() Method

## Description

The java.lang.StrictMath.sqrt() method returns the correctly rounded positive square root of a double value.It include these cases −

• If the argument is NaN or less than zero, then the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is positive zero or negative zero, then the result is the same as the argument.

or else, the result is the double value closest to the true mathematical square root of the argument value.

## Declaration

Following is the declaration for java.lang.StrictMath.sqrt() method

```public static double sqrt(double a)
```

## Parameters

a − This is the value to be used.

## Return Value

This method returns the positive square root of a.

NA

## Example

The following example shows the usage of java.lang.StrictMath.sqrt() method.

```package com.tutorialspoint;

import java.lang.*;

public class StrictMathDemo {

public static void main(String[] args) {

double d1 = 121 , d2 = -729, d3 = 0.0;

// returns the positive square root of a double value.
double sqrtValue = StrictMath.sqrt(d1);
System.out.println("square root of " + d1 + " = " + sqrtValue);

sqrtValue = StrictMath.sqrt(d2);
System.out.println("square root of " + d2 + " = " + sqrtValue);

sqrtValue = StrictMath.sqrt(d3);
System.out.println("square root of " + d3 + " = " + sqrtValue);
}
}
```

Let us compile and run the above program, this will produce the following result −

```square root of 121.0 = 11.0
square root of -729.0 = NaN
square root of 0.0 = 0.0
```
java_lang_strictmath.htm