ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Fri, 24 Oct 2014 17:16:29 +02002nd-order ODE: Maxima wants sign of 1 constant before finishinghttps://ask.sagemath.org/question/24624/2nd-order-ode-maxima-wants-sign-of-1-constant-before-finishing/ I'm trying to solve a 2nd-order nonlinear ODE using desolve(). Maxima gets partway through, but then asks for the sign of one of the integration constants. How can I tell it to assume something that doesn't exist before I call desolve()?
t,P,x0=var('t,P,x0')
x=function('x',t)
de=(diff(x,t,2)*x^2+P==0)
forget()
assume(P>0,x0>0)
desolve(de,x,ics=[0,x0,0],ivar=t)
gives the error:
TypeError: ECL says: Maxima asks: Is %k1 positive or negative?
Hoss N. FefferFri, 24 Oct 2014 17:16:29 +0200https://ask.sagemath.org/question/24624/