Hi, I've just tried some math functions in python3.0, but there's an 
wrong calculation (see the example). sin(pi/4) should be same as 
(2^.5)/2, but the result is different in last two digits. I don't know 
if it's an expected behaviour and this is my first posted issue. 

Python 3.0rc1 (r30rc1:66507, Sep 18 2008, 14:47:08) [MSC v.1500 32 bit 
(Intel)]
>>> from math import *
>>> sin(pi/4)==(2**0.5)/2
False

sin(pi/4)==0.70710678118654746
(2**0.5)/2==0.70710678118654757

bubersson

None of these calculations are going to work out exactly.  Look-up "what
every computer scientist needs to know about floating point" and see the
floating-point appendix in the Python tutorial.  In this case, the
difference is only one bit in the last place:

  >>> 0.70710678118654746.hex()
  '0x1.6a09e667f3bccp-1'
  >>> 0.70710678118654757.hex()
  '0x1.6a09e667f3bcdp-1'