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seen Jul 21 at 17:43

Jul
18
awarded  Nice Question
Nov
29
awarded  Popular Question
Oct
17
comment Self Study in Dynamical Systems
Unfortunately, the link you've provided appears to be broken.
Oct
16
awarded  Popular Question
Jul
17
awarded  Popular Question
Jul
14
awarded  Notable Question
Feb
1
awarded  Popular Question
Sep
2
awarded  Nice Question
Mar
22
awarded  Yearling
Aug
29
accepted Recommendation for a book and other material on dynamical systems
Aug
11
comment Recommendation for a book and other material on dynamical systems
I just ran across this course, for others who are interested: youtube.com/watch?v=mkfU9zVNGkQ&feature=relmfu
Aug
11
answered Reference request: coding in dynamical systems
Aug
11
asked Recommendation for a book and other material on dynamical systems
Jun
28
comment Online tools for doing symbolic mathematics
+1, this looks like an interesting tool.
Jun
27
comment Online tools for doing symbolic mathematics
It's as though everything lately has been telling me to learn Python. +1 for answering with precisely what I asked for: a web-based app that provides symbolic manipulation that isn't limited to one-liners.
Jun
22
comment Using differentials
@Noteventhetutorknows - The fractional notation helps give the notion of rates, but it also gives the impression you can just do normal algebraic manipulations on them -- which is definitely not true. It can be done, as Americo Tavares points out, but it must be done very carefully and rigorously.
Jun
22
comment Using differentials
+1 because it has the potential to generate answers to help explain proper use of differentials.
Jun
22
comment Using differentials
@Theo - That's fine. What affect does \$\$ have?
Jun
22
comment Using differentials
@Noteventhetutorknows - re: dubiousness, I was specifically referring to the homogeneous equation I wrote, but what you wrote is fraught with what I would consider to be inappropriate manipulations. The chain rule gives: $\frac{dy}{dx} = \frac{dy}{dt}\frac{dt}{dx}$. Nothing about the chain rule says it's safe or valid to swap denominators as though $\frac{dy}{dt}$ is a simple fraction.
Jun
22
comment Using differentials
Agreed. When I took my ODE class I just went with it, but as I went back and worked through some of that material years later it occurred to me that the homogeneous equation above is actually a partial differential equation in disguise, of sorts -- hence my addendum with $\frac{dy}{dt}$ (etc). Adding $t$ explicitly seemed to make it easier to 'guess' the solution for those problems.