On Fri, Feb 19, 2016 at 8:45 AM, Aaron Meurer <[email protected]> wrote: > trigsimp() will convert the sin to cos. To remove the negative and > square, you'll have to use expand_log(force=True), which gives a > complex constant (which can be ignored, since this is an integral). > > It would definitely be better if integrate at least gave log(1 - > sin(x)**2) so that the result is real.
Here is a code that does this: In [1]: expand_log(integrate(tan(x), x).trigsimp(), force=True) Out[1]: -log(cos(x)) - I*pi/2 Ondrej > > Aaron Meurer > > On Fri, Feb 19, 2016 at 8:07 AM, Carsten Knoll <[email protected]> wrote: >> I want to calculate the antiderivative for tan(x) >> >> In [4]: x = sp.Symbol('x', real=True) >> >> In [5]: sp.integrate(sp.tan(x), x) >> Out[5]: -log(sin(x)**2 - 1)/2 >> >> >> This result is technically correct, but I would (for didactic purposes) >> prefer something like >> >> -log(cos(x)). >> >> How can I achieve this? >> >> Thanks. >> Carsten. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/56C71381.4090204%40gmx.de. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CAKgW%3D6JnGtQ2-40XA2kSyD%3D7J%3D1futiJx2z7ocr53T0UrW%3DpLw%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CADDwiVA%3DK7zMNjEYizfFDzqgf_2J6OjcHBC8wJ8amBcDr%2BKcVw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
