Question about third-order ODE.

Q: The exact solution to the differential equation (t^2/0.357)f'''-(1/0.3)f'+f = t^0.3+5 is given in the figure below.
Starting with an initial condition f(2) = 6.2311, f'(2) = 0.1847 and f''(2) = -0.0646, Euler's method will over predict the solution when computing f(4).
From my following codes, I found out the graph is over predict with Euler's method, but I don't know how to get draw the exactly same graph as shown above. How could I plot the same graph?
function du = dfdeta(t,f)
du = [f(2); f(3); 1.19/t^2*f(2)-0.357/t^2*f(1)+0.357*t^(-1.7)+1.785/t^2];
and
[eta,f] = eulsys(@dfdeta,[2 4],[6.2311 0.1847 -0.0646],.01);

1 commentaire

Star Strider
Star Strider le 26 Avr 2015
The Euler Method is an approximation. As the Wikipedia article (link) discusses, you cannot expect it to match an exact solution.

Connectez-vous pour commenter.

Réponses (0)

Catégories

En savoir plus sur Numerical Integration and Differential Equations dans Centre d'aide et File Exchange

Produits

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by