Java - Math.sqrt() method example

Math sqrt is a static method that returns a number which is the square root of input value. The method works only on positive real numbers.

public class MathExample {

    public static void main(String[] args) {
        System.out.println( Math.sqrt(  4   ) ); //  2.0
        System.out.println( Math.sqrt(  9   ) ); //  3.0

        System.out.println( Math.sqrt(  2   ) ); //  1.4142135623730951
        System.out.println( Math.sqrt(  0.5 ) ); //  0.7071067811865476
        System.out.println( Math.sqrt(  0   ) ); //  0.0
        System.out.println( Math.sqrt( -1   ) ); //  NaN
    }
}

1. Documentation

package java.lang;

public final class Math {

    public static double sqrt(double number) { ... }

}

2. Square root with Math.pow method examples

In this example, the way how to calculate square root using power function is presented. 

public class MathExample {
    
    static double calculateSqrt(double value) {
        return Math.pow(value, 0.5);
    }

    public static void main(String[] args) {
        // Examples:
        System.out.println( calculateSqrt(  4   ) ); //  2
        System.out.println( calculateSqrt(  9   ) ); //  3

        System.out.println( calculateSqrt(  2   ) ); //  1.4142135623730951
        System.out.println( calculateSqrt(  0.5 ) ); //  0.7071067811865476
        System.out.println( calculateSqrt(  0   ) ); //  0
        System.out.println( calculateSqrt( -1   ) ); //  NaN
    }
}