/* Use System.out.format to maintain the precision of the double value */
/* Try to read books like Core Java Vol 1, if u are a beginner. */

public class SquareRoot {
    public static void main(String[] args) {
        System.out.println("Number \t SquareRoot");
        for (int i = 0; i <= 20; i = i + 2) {
            System.out.format("%d \t %1.4f \n", i, Math.sqrt(i));
        }
    }
}

/* Output */
/*
Number      SquareRoot
0      0.0000
2      1.4142
4      2.0000
6      2.4495
8      2.8284
10      3.1623
12      3.4641
14      3.7417
16      4.0000
18      4.2426
20      4.4721
*/