how to write to solve this type of system of equations ?
1 visualizzazione (ultimi 30 giorni)
Mostra commenti meno recenti
Risposte (2)
Wan Ji
il 12 Set 2021
Hey friend
Just expand the left items of the two equations, extract u'' and v'', then an ode45 solver is there for you.
0 Commenti
Walter Roberson
il 12 Set 2021
Modificato: Walter Roberson
il 12 Set 2021
I was not able to figure out what is being raised to 10/9 . I used squiggle instead.
syms u(r) v(r)
syms N squiggle real
assume(r, 'real')
du = diff(u);
dv = diff(v);
left1 = diff(r^(N-1)*du^3)
right1 = r^(N-1) * sqrt(u) * sqrt(v) / (3*r^(2/3) * sqrt(1 + 9*squiggle^(10/9)/(10*(3*N-2)^(1/3))))
left2 = diff(r^(N-1)*dv^3)
right2 = r^(N-1) * u * v / (3*r^(2/3))
eqn1 = left1 == right1
eqn2 = left2 == right2
ic = [u(0) == 1, v(0) == 1, du(0) == 0, dv(0) == 0]
sol = dsolve([eqn1, eqn2, ic])
string(eqn1)
string(eqn2)
string(ic)
Lack of a symbolic solution means that you would have to do numeric solutions -- but you cannot do a numeric solution to infinity, and you certainly would not get a formula out of it.
5 Commenti
Vedere anche
Categorie
Scopri di più su Symbolic Math Toolbox in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!