Yeah, it seems that that is what happens (look at the indefinite integral).
Aaron Meurer On Thu, Mar 22, 2012 at 3:42 PM, Ilya Schurov <[email protected]> wrote: > Hi there, > > integrate() seems to have a bug which leads to wrong answers for > rational trigonometric functions. E.g. > > In [7]: integrate(1/(cos(x)+2),(x,0,2*pi)) > Out[7]: 0 > > It's obvious that the answer is wrong: the function is strictly > positive everywhere, so integral cannot be 0. > > It seems (I didn't check it) that SymPy uses trigonometric > substitution like u=tan x/2 and then incorrectly substitute 0 and 2*pi > as limits. (There are singular points in the interval (0,2*pi) for tan > x/2, so it does not work.) > > See an issue on the tracker: > http://code.google.com/p/sympy/issues/detail?id=3179 > > Thanks! > > -- > Sincerely yours, > Ilya V. Schurov. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
