MuPAD Differential equation solver

I tried following the directions from:

http://www.mathworks.com/help/toolbox/mupad/pdflinks/tutorium.pdf

on pg 8-12, but for some reason i'm getting an error with my syntax. I think it doesnt like how i'm writing apostrophe when i write y'(x).

Someone give me some ideas on how to make it work?

Thank you!

[bym]

are you using the notebook interface?

[Kenneth]

no i'm not that's probably the problem

[bym]

not necessarily, but maybe. What is your equation?

[Kenneth]

I was just trying to do the example from the pdf file i found

I've written it as diffequation = ode(y'(x)-y(x)^2,y(x)) and it gives me the syntax error in matlab saying unexpected parenthesis or notation. I've never really used MuPAD before so I'm not sure how it works

Answer 1

[bym]

Try using dsolve from the matlab command window. y'(x) would be 'Dy' as in

dsolve('Dy = x',<initial conditions>,'x')

Edit

so for the example it should be:

syms x y;
dsolve('Dy-y^2','x')

 - untested -

[Kenneth]

That was really helpful! Thank you very much!

[Kenneth]

Do you know if you can do higher order differential equations with the dsolve?

[Kenneth]

Nevermind. I read the instructions on dsolver more carefully. Thank you very much again! Really appreciate it

Answer 2

[Billy]

2 things:

• Be very careful to enter y(x) (never just plain y).
• In the MuPad statement you included with your comment, you need a colon:

    diffequation = ode(y'(x)-y(x)^2,y(x))

Should be:

    diffequation := ode(y'(x)-y(x)^2,y(x))

instead

You can then

    solve( diffequation )