sin(x)^2+cos(x)^2 = 1 on different calcs

[Albert Chan]

(09-26-2018 05:27 AM)cyrille de brébisson Wrote:  =100-99.99-0.01 -> 5.1157E-15
shows that it does not "move small differences to 0....

The difference is not small, if think in ULPs (above case, 1 ULP = 2^-59):

100 - float(99.99) = 0x147ae147ae2000 ULP
float(0.01) = 0x147ae147ae147b ULP

Difference = 0x2000 - 0x147b = 2949 ULP

Quote:However, I have NO clue what might be going on with
=1/3+1-1-1/3 and =(1/3+1-1-1/3)

I am using *old* MS Excel 95.
It does not have set-to-zero "feature".
So, both expressions return the same -5.6E-17