Why do we assume that g'(t).diff(g(t)) == 0? Here's a question on math.SE about derivatives w.r.t. functions: https://math.stackexchange.com/questions/954073
Does the assumption work with the accepted answer there? On Wednesday, August 29, 2018 at 2:12:07 AM UTC-4, Aaron Meurer wrote: > > I believe they are equal, according to SymPy's rule that > (g'(t)).diff(g(t)) == 0: > > f(g(t)).diff(t, g(t)) == (f'(g(t))*g'(t)).diff(g(t)) == f''(g(t))*g'(t) > > f(g(t)).diff(g(t), t) == f'(g(t)).diff(t) == f''(g(t))*g(t) > > You can also verify this with SymPy: > > >>> f(g(t)).diff(t).diff(g(t)) > Derivative(f(g(t)), (g(t), 2))*Derivative(g(t), t) > >>> f(g(t)).diff(g(t)).diff(t) > Derivative(f(g(t)), (g(t), 2))*Derivative(g(t), t) > > Aaron Meurer > > > On Tue, Aug 28, 2018 at 11:55 PM, Chris Smith <[email protected] > <javascript:>> wrote: > > SymPy allows derivative wrt non-Symbols. Under the current assumptions, > > `g(t).diff(g(t),t) == g(t).diff(t, g(t)) == 0`. Can anyone give an > example > > where `f(g(t)).diff(t, g(t))` would not equal `f(g(t)).diff(g(t), t)`? > > > > -- > > 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] <javascript:>. > > To post to this group, send email to [email protected] > <javascript:>. > > 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/73c688ce-d447-4767-8ded-373346b822b7%40googlegroups.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/22f5c508-94ba-44f9-bd73-0d1f65f90330%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
