Recent content by Gaco

Thank you for the suggestion. The solution was given on the official wolfram forum and was to use the transformation rule, the /. operator and make the third line as this: D[f[u], {{x[u], y[u]}}]/.{x->Exp,y->Cos} That way the fints the gradiant from the general expression, then substitutes in...

Hi everyone. I've been using basically a whole day on two trivial Mathematica issues, so I'm finally going online for help: 1. Is there any simple way to define the gradient as a new function as such? My try: Clear["Global`*"] f[u_] := x[u]*y[u] gradf[u_] := D[f[u], {{x[u], y[u]}}]...

[SIZE="4"]On divergence I think it's a bit hard to come from a cartesian understanding of divergence (and Laplacian operator for that matter) and then understand the same in terms of spherical polar coordinates intuitively? I mean, say that a vector field is v = x i where i is the...

I spend a lot of time on google and various webpages yesterday to investigate all kind of board solutions. At some point I stopped upon a glassboard, yes yet a third third kind hehe. I really like the looks of this one: http://www.polyvision.dk/english/glassboards.htm As with the chalkboards...

I don't know if it's a good description. Everytime I read through the textbook I write down on paper the most important points. I never save these notes, I throw them out afterwards, but I do it because I learn and remember a subject faster if I write it down actively as opposed to just reading...

As I said, it won't be a replacement, just a supplement, an additional resource that won't take much time away from my scribbling on paper. I imagine that I'm still going to speed-write notes and problems as I read the book as I do now, and that I will just review larger sections OR smaller...

Hehe you may be right. But the idea is stuck in my head now, so I have to try it. If the concept fails, I will sell it secondhand and take it as experience. By the way I'm not going to "stare" at the equations all day long. Trust me, I don't mistake memorization as the primary component of...

I haven't tried having it yet so I can't say for sure, but I tend to disagree for reasons in my post above yours; I simply like the idea of having material (mathematical theorems, physical laws etc.) from my current focus in my environment, on the wall. Sort of like a non-permanent image...

For clarification the purpose of the writing board will primarily be to contain the material I'm reading at any given moment in the textbooks. The benefits are two-fold: I get to write down the things I read for better memorization, but unlike doing this on pen and paper I get to see the...

That's what I've been thinking as well. But then again, I thought that if I bought a real quality blackboard and some real quality chalk and was careful to wash the chalk eraser often, the dusting wouldn't have to be so bad at all. This is only pure speculation though, I have no experience with...

Come to think of it, Leonard and Sheldon in "The Big Bang Theory", the TV-series, they have whiteboards and they are experimental and theoretical physicists respectively. Of course it's fiction but still makes it a bit more plausibel to use whiteboards. Hehe I know it seems silly, but it just...

I'm getting a writing board for my college room (and I wonder why I haven't done it sooner!). I just can't decide between a blackboard and whiteboard. I really like the tactile response of a blackboard, psychologically it kind of invites me more to use just as a brainstorm board, to write...

Oh I did understand it the first time around, I was just expressing my gratitude and relief. Thanks anyway :) But look now I didn't go to bed promptly, but continued to ponder around something about the dot product.. how stupid of me, I'm going to hate myself tomorrow when the alarm goes.

The time is way past my ideal bedtime for tomorrow mornings lecture, I've been staring at my books for a couple of hours now. I came to read that post through a google search and now I finally understand WHY that method for finding inverse matrix's work. It's so obvious, I guess I'm exhausted...

Ok thanks for the answer. Have you read Michael Spivak's Calculus, how do them two compare to it?