Why are my assertEquals not working?

I am testing one of my methods double getSqrt(double s)

and having the following JUnit test code:

@Test
public void testGetSqrt() {
    System.out.println("getSqrt");
    double s = 16.0;
    Calculator instance = new Calculator();
    double expResult = 4.0;
    double result = 4.000000000052429; // was "instance.getSqrt(s);" here
                                       // now hardcode for test purpose
    System.out.println(System.getProperty("java.class.path"));
    assertEquals(expResult, result, 0.0);
}

      

        
        
        
      

    

It failed every time, no matter how I changed the tolerance "0.0", "0.1", "0.00", "0.01", "0.001" .... The report is as follows:

AssertionFailedError: expected: <4.0>; but was: <4.000000000052429>

I am using JUnit 4.12 and Hamcrest 1.3.

And my import:

import org.junit.Test;
import static org.junit.Assert.*;

      

        
        
        
      

    

Did I misuse the assumption?

Console output:

compile-test-single:
Testsuite: descriptivestatisticsapplication.processing.CalculatorTest
getSqrt
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.079 sec

------------- Standard Output ---------------

getSqrt

C:\Java\jdk1.8.0_111\jre\lib\javaws.jar;C:\Java\jdk1.8.0_111\jre\lib\deploy.jar;C:\Java\jdk1.8.0_111\jre\lib\plugin.jar;C:\Users\Z\Documents\NetBeansProjects\DescriptiveStatisticsApplication\build\classes;C:\Program Files\NetBeans 8.2\platform\modules\ext\junit-4.12.jar;C:\Program Files\NetBeans 8.2\platform\modules\ext\hamcrest-core-1.3.jar;C:\Users\Z\Documents\NetBeansProjects\DescriptiveStatisticsApplication\build\test\classes;C:\Program Files\NetBeans 8.2\extide\ant\lib\ant-launcher.jar;C:\Program Files\NetBeans 8.2\extide\ant\lib\ant.jar;C:\Program Files\NetBeans 8.2\extide\ant\lib\ant-junit.jar;C:\Program Files\NetBeans 8.2\extide\ant\lib\ant-junit4.jar

------------- ---------------- ---------------

      

        
        
        
      

    

Update 5/27:

After running some of the tests from the comments in the comments, this unit test can now pass successfully. I think this question can be closed.

I'm worried that I haven't found a reason why this failed, and why it works now! Same code, same logic! The only thing I did was comment out some of the non-important lines and then add them back, change some of the declaration statements and then change them. The same code has different types of behavior. I didn't change anything in the building and ran env and libs. It doesn't make any sense. The result from the code snippet should be reproducible.