Dave

wolfson: you should probably say where you got something from if you just lifted it from a website. (i.e. http://users.aol.com/AmazingMazeMan/primes/negative.html in this case). I'm not trying to be pedantic or anything, but it is part of our forum rules to give proper credit where due.

I don't think negative numbers can be prime. If you take -2 for example, its divisors could be thought to be 1, -2 and 2, which would imply it not being prime.

nice. if somewhat of a waste of a very nice pickled onion.

Hmm. Have my doubts about the gentle and caring bit myself; I know quite a lot of people who are both (or one or the other) but most of those don't go around shooting/gassing people that are 'impure'.

Well done Hope you enjoy teh new job

moo? I love conspiracy theories. They also make fairly decent films sometimes.

I'm not saying all 15-16 year olds can't do calculus - I know personally of quite a few that can - but the majority of them probably can't. Making sure you have a fairly solid foundation to build on before you start doing calculus is something that is absolutely essential. Trust me on this one, because I had to play catch-up bigtime when it came to A-levels. So stick at it, it pays off in the end A good question would perhaps be something like proving that if a mirror takes the form of a hyperbola then all parallel beams of light which are also parallel to the x-axis of the mirror meet at the focus of the hyperbola. This is a fairly researchable type problem, but I daresay the proof is widely available elsewhere on the net. I'll try and dig out some of my old questions from around here somewhere and get back to you.

What kind of age range are you after? If you're setting it for say 15-16 year olds then obviously calculus and things like that can't be involved. From the y = mx + c argument type thing, you could ask them to do something like prove that the equation of a line through a fixed point (x1, y1) with gradient m is (y - y1) = m(x-x1), or get them to find the equation of a line that passes through 2 fixed points. More information required

Revolutions did completely suck compared to the other two. They tried to make it too deep when to be honest they didn't need to. The entire thing was a bit silly really. (hi btw, been at uni == not much if any posting)

I don't think the purpose is to find a numerical solution, but rather to re-arrange the equation such that you get a function y = f(x).

?

Looks fine on my iMac using camero (or whatever Chimera changed its name to).

Well, if you're going to buy it in lake sized quantities, then yes. Otherwise, probably not.

If you want a proper discussion on the flaws of your "model", then I suggest that you first provide some evidence for it, rather than quoting a lot of numbers along with some units. I find people that misquote what I say to be both quite annoying and immature. If you want to have a discussion about theoretical physics, fine, go for it. If you want to post this kind of inane rubbish with no mathematical proof and no experimental evidence, then I suggest you go elsewhere.

I would say those results are pretty much screwed up. I just plotted them and they really suck, I have to say. You need to ensure that the intensity of the light being shone on the cell is constant or the entire results set don't come out right.

I gave up replying seriously to this sort of stuff ages ago

one word: retarded.

Good luck on that one. On a sidenote, the piccies are indeed pretteh.

I can't believe I just read that :\

I certainly can't find a solution and I've been thinking about it for the best part of 2 days now

The trouble with wolfram is that it's all highly technical. I shouldn't worry too much about it if you don't have a solid foundation in mathematics.

Who knows? I certainly can't be bothered messing around with that stuff at this time of night

Unfortunately not. The posts appear to all be highly technical in nature and I'm not very much inclined to wade through them.

Unfortunately, modular forms are (on the mathematical scale of things) quite advanced. I'll freely admit that I know nothing about them at all other than their relationship to the proof of Fermat's Last Theorem. On the undergraduate scale, elliptic equations are covered in either the third or fourth year as an optional module (at Warwick and most other universities I've seen). I'm not quite sure where modular forms fit in. Sorry I can't be of moe help.

Well, that kindof sums it up bluntly, but yes e.g. x dy/dx = y