Il giorno mercoledì 31 ottobre 2018 10:11:34 UTC+1, Francesco ha scritto: > > Hello; I have installed sage 8.4 and I have problem with the derivatives > ... > I have defined a function in sage of this type: > > x=var('x') > def funz(x): > if x >= 0: > return x^2 > else: > return x^3 > > but, when I try to calculate > > diff(funz(x),x) > > I obtain only > > 3x^2 > > and this is wrong !! Can you help me ? >
Ok, the piecewise-defined functions can be written with the sign(x) function. The funz(x) can be written as: funz(x)=(x^2)*(sign(x)+1)/2+(x^3)*(-sign(x)+1)/2 -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.