201671010127 2016-2017-2 problems encountered in Java programming

After learning some basic Java grammar, the excitement of the mind can not be restrained, always compare the differences between Java and C language Grammar, a free time will be used to learn the basic Java grammar to write some simple procedures. This does not, accidentally and into the difficulties, I sincerely ask you friends, how to solve my problem, the following attached to my problems.

I wrote the same program in Java and C, are using Newton iterative method to open the square, but the results of the two have some small differences, to the forum after consulting, the feeling is related to their own compiler bad environment, Java compiler is 64-bit, and C language compiler is 32-bit, I just want to know if there's any other reason than that? I implore the great God to give me help, thank you! Attached below.

C Language:

Java language:

201671010127 2016-2017-2 problems encountered in Java programming