sqrt() Method

Here is sample output from the (unmodified) program:

C:\chap11>java SquareRoot
Enter a double: 3
square root   : 1.7320508075688772

It is OK to enter a number without a decimal point (as the "3" above) for floating point I/O. Java converts it to the correct type. Here is some of the documentation for the method sqrt():

static double sqrt(double a) 
Returns the correctly rounded positive square root of a double value. 

This was copied from the Java documentation at http://java.sun.com/javase/6/docs/api/. Search for "sqrt Java" with a search service (like Google) when you need it.