Java Math sqrt() Method

The Math.sqrt() method is a part of java.lang.Math package. This method is used to calculate the square root of a number. This method returns the square root of a given value of type double. In this article, we are going to discuss how this method works for regular values and for special cases such as infinity and NaN.

Special Cases:

• If the argument is positive, then the method will return the square root of the number.
• If the argument is negative, then the method will return NaN.
• If the argument is positive infinity, then the method will return positive infinity.
• If the argument is NaN, it returns NaN.
• If the argument is zero, then the method will return zero.

These special cases make sure that the Math.sqrt() methods work correctly.

Syntax of sqrt() Method

public static double sqrt(double a)

• Parameter: This method takes a single parameter a, of type double, whose square root need to be calculated.
• Return Type: This method returns the positive square root value of the argument passed to it. And for the special cases, we mentioned above.

Now, we are going to discuss some examples for better understanding and clarity.

Examples of Java Math sqrt() Method

Example 1: In this example, we will see the square root of positive numbers.

// Java program to demonstrate the 
// working of Math.sqrt() method
import java.lang.Math;

class Geeks {
    
    public static void main(String args[]) {
        
        double a = 30;
        System.out.println(Math.sqrt(a));  

        a = 45;
        System.out.println(Math.sqrt(a));  

        a = 60;
        System.out.println(Math.sqrt(a));

        a = 90;
        System.out.println(Math.sqrt(a));
    }
}

5.477225575051661
6.708203932499369
7.745966692414834
9.486832980505138

Explanation: Here, we are calculating the square root of different numbers like 30, 45, 60 and 90.

Example 2: In this example, we will see how the sqrt() method handles special cases like NaN, negative values and posititve infinity.

// Java program to demonstrate working 
// of Math.sqrt() method for special cases
import java.lang.Math; 

public class Geeks {
    
    public static void main(String[] args) {
        
        double p = Double.POSITIVE_INFINITY;
        double n = -5;
        double nan = Double.NaN;
        double res;

        // Here the agument is negative
        res = Math.sqrt(n);
        System.out.println(res);  

        // Here the argument is positive infinity
        res = Math.sqrt(p);
        System.out.println(res); 

        // Here the argument is NaN
        res = Math.sqrt(nan);
        System.out.println(res);  
    }
}

NaN
Infinity
NaN

Explanation: Here, we are handling special cases such as NaN and Infinity. When the given argument is negative and NaN then we will get NaN as an output, and when the argument is positive infinity then we will get infinity.