Bill Goodwine's Courses

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By "exact" I don't mean an exact differential equation, but rather one you can find a solution for in terms of elementary functions.

Is it possible to do numbers 2 and 3 with MATLAB? Or would Fortran be preferred?

jmcgill1 wrote:Is it possible to do numbers 2 and 3 with MATLAB? Or would Fortran be preferred?

A compiled language such as FORTRAN, C, C++, or go is required. I had announced this in class on Friday.

Someone asked me

Can my equation for number 2 on the homework be dx/dt=cos(t) ? Or does that not depend on both x and t?

No, your

f(x,t) = cos(t)

which only depends on t.

When it says "plot the error versus different time steps" in problems 2 and 4, does that mean a plot of error at a certain value of t vs. deltaT, or error vs t with curves for different deltaT values like we did in class today?

tbest wrote:When it says "plot the error versus different time steps" in problems 2 and 4, does that mean a plot of error at a certain value of t vs. deltaT, or error vs t with curves for different deltaT values like we did in class today?

Thanks. It should be more precise: "Plot the error versus time for different delta t." So curves of error vs t, and different curves for different dt.

For number 2, do we make up our own initial conditions as well?

colsen3 wrote:For number 2, do we make up our own initial conditions as well?

Yes

Someone asked me wrote:I was wondering if we can use ode45 to find the exact solutions of the equations.

If you think you can trust it. The last problem shows pretty clearly that you can't always trust it.

Would you like us to include our fortran code with the homework?

Jfox10 wrote:Would you like us to include our fortran code with the homework?

Yes, definitely.