How to set several initial conditions when solving an ODE?

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Sergio Manzetti
Sergio Manzetti le 29 Déc 2017
Commenté : Sergio Manzetti le 29 Déc 2017
Hi, I have the following ODE:
if true
% code
end
syms a h Y(x) g x B E
eqn = (h)*diff(Y,x, 2) + (g)*diff(Y,x) + (g^2 - E)*Y == 0;
cond = Y(0) == 1;
cond = (diff(Y)(0) == 0;
Y(x) = dsolve(eqn, cond)
and would like to add Y'(0)= 0 as initial condition, however cond = (diff(Y)(0) == 0; does not work. How can I combine two conditions here?
Thanks!

Réponse acceptée

KSSV
KSSV le 29 Déc 2017
Check this demo from the documentation:
syms y(t) a b
eqn = diff(y,t,2) == a^2*y;
Dy = diff(y,t);
cond = [y(0)==b, Dy(0)==1];
ySol(t) = dsolve(eqn,cond)
  1 commentaire
Sergio Manzetti
Sergio Manzetti le 29 Déc 2017
Hi KSSV, I did this and it worked, however I am puzzled given that I still get a constant "C11" in the answer, when two conditions are given. Is this a typical example where further conditions are required to get "rid of" C11?

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