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.Tue, 27 Nov 2018 06:09:05 +0100I'm trying to substitute a value in a Laplace transformhttps://ask.sagemath.org/question/44466/im-trying-to-substitute-a-value-in-a-laplace-transform/ Hello, I'm trying to solve a DE by using Laplace transforms, but when I get the lapalce transfrom of my DE I get this part s*D[0](y)(0) and I don't know how can I substitute D[0], I tried D[0](y)(0) == -1) but I get an error that says that D is not defined, I can subs y(0) == 1 with no issues. So my question is how can I substitute the value for y'(0)=-1 in the Laplace transform.
thank you for your help !.
t = var('t')
s = var('s')
y = function('y')(t)
ED = diff(y,t,2)-2*diff(y,t)-3*y==4
ED_Lap = ED.laplace(t,s)
ED_Lap = solve(ED.laplace(t,s),laplace(y(t), t, s))
print(ED_Lap)
show(ED_Lap[0].rhs().subs(y(0)==1,D[0](y)(0)==-1).inverse_laplace(s,t)) # I don't know how to subs DbemolTue, 27 Nov 2018 06:09:05 +0100https://ask.sagemath.org/question/44466/