Note : in your question in Julia Discource, you state that your areao of revolution is 2*pi*integrate(f(x)*sqrt(1+f(x).diff(x)), (x, a, b)).
I beg to differ : it should be 2*pi*integrate(*abs*(f(x))*sqrt(1+*abs*(f(x).diff(x))), (x, a, b)). In your specific case, both f(x) and f(x).diff(x) are positive on [1 3], so there is no numerical difference. BTW : Mathematica can get you an explicit expression for your integral, involving hypergeometric functions, but fails to compute its numerical values. HTH, Le dimanche 15 janvier 2023 à 08:36:14 UTC+1, zaqhie...@gmail.com a écrit : > Hi all, > > I have a question: why SymPy (in JULIA and PYthon) unable to get the > numerical answer for area of surface of revolution? > > Is it impossible? > > This is my question posted today on Julia Discourse: > > > https://discourse.julialang.org/t/area-of-surface-of-revolution-integral-too-hard-to-be-computed-by-julia-sympy-and-python-sympy/92981 > > -- > С наилучшими пожеланиями, Богиня Фрейя > Atenciosamente, Freya the Goddess > Meilleurs voeux, Freya the Goddess > Liebe Grüße, Freya the Goddess > Best wishes, Freya the Goddess > よろしくお願いします、Freya the Goddess > 最好的祝福，Freya the Goddess > Matakwa mema, Freya the Goddess > مع أطيب التمنيات ، فريا الإلهة > -- 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 sympy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/d8b5255a-9a17-4196-aced-c38b549076b0n%40googlegroups.com.
