Solved by KFrank in post #2 
              
              
                Hi Hoang! 

Here a is only printed out to four decimal digits.  That is, a[0][0] 
is a number close to, but not actually equal to 0.7576.  Perhaps 
a[0][0] = 0.75758379. 

Here you compare a[0][0] (as well as the rest of a) with 0.7576. 
But a[0][0] is only approximately equal 0.7576 (equal only to …