Question

I am trying to take two numbers and get the square of them. Using several numbers some work, but this one is giving me problems pow(.0305,2). Using a calculator i get an answer of: 0.093025; but when I use java i get an answer of:9.609999999999999E-4. I need .0305 because I am taking 3.05/100 which is .0305.

I have found through trial that if I do .pow(.305,2), that does give me my need answer, but then I would have to get that with 3.05/100.

EDIT:(adding code)

double weight=3.05;
double TapeLength=100.00;
double ftwt= weight/TapeLength; this gives me: 0.093025
double ftwt= Math.pow(ftwt,2); //this gives me: 9.3025E-4 

everything is cast as a double.

Answer 1

If you’re really getting 9.609999999999999E-4 as the result, you’re doing something wrong other than what you have in you question. The following code (in Eclipse 3.7.1):

class Test {
    public static void main(String args[]) {
        double dd = .0305;
        System.out.println (Math.pow(dd, 2));
        System.out.println ("%.8f\n", Math.pow(dd, 2));
    }
}  

produces:

9.3025E-4
0.00093025

which are both correct ^(a), just expressed in different output formats. The default for double is exponential format in this case but the last line shows how you can get different formats.

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^(a) Just on the off chance that you’re confused by the exponential form (based on your comments), 0.00093025 is the same as 9.3025E-4 since the latter means9.3025 x 10-4 (9.3025 with the decimal point shifted four positions to the left.