Recent content by adoado

The combination of potassium nitrate and sorbitol and commonly used by hobbyists as a propellant for rocket motors. The combustion equation is given below: I have a few very simple questions based on the chemistry of such a reaction. Firstly, many people do not use stoichiometric...

Awesome, thanks a lot for the replies! Using your myspeedybob as a guide, I found this: http://www.tpub.com/content/et/14086/css/14086_34.htm It explains pretty much exactly what you said. So I guess as a general rule, assume the resistance of the body is R = 1500 Ω. Then, find the current...

Hey guys, My understanding of circuit analysis and the like is very minimal, and I have had a certain lack of understanding about something for a long time, and I feel I need to get a solid answer. I understand the fundamental difference between a voltage or potential difference and a...

Hey everyone! I was recently scribbling on paper, and after a series of ideas, I got stuck with a problem. That is, can I find out if there exists some integers A and B such that C=2^{A}3^{B} For some integer C? For an arbitrary C, how do I know whether some A, B \in \textbf{Z}...

I use CurveExpert to find best fit models; give that a try. Then simply evaluate a few points from the model and plot them as separate data.

Hey all, I recently encountered a problem that I cannot seem to solve... Let's say I have the following coins A, B, C, D and E, each one with an associated integer value such that: A = 1 B = 2 C = 3 D = 4 E = 5 Let's say I can pick N of them, and order does matter (so ABC is not...

Hello all, Given two 3D lines described by the general equation \vec{L(t)}=\vec{p}+\vec{d}t I found a way to find their intersection point, but it uses the cross product in the derivation. I am assuming a 4D line is a valid thing? And can be described the same way? (except with 4 element...

Clear the variables; if you have stored x as a constant (given it a value) then you will get a numerical result.

Awesome, thanks a lot Redbelly! Really appreciate that! :)

I am not sure the reasoning to it, or exactly what you mean :-p Able to elaborate on the reasoning of this? Cheers! Adrian

I recently encountered another problem, but it extends this topic. Instead of opening a new thread I guess this place is as good as any.. If one defines the function E=|1-x-y| + |4-2x-y| ... how can I find it's minimum now (x and y coordinates)? Can this be extended to N variables inside each...

Hello all, Is there a closed form expression for the convergence of C(s) = \sum_{n=1}^{N} n^{s} Cheers, Adrian

Isn't that separable? Split up the differentials?

Hmm... you can still get x'(t) and y'(t) by differentiating implicitly t(x) and t(y), but you will be left with derivatives still partially in terms of x and y... Edit: I am not sure if this is valid, but as you are evaluating the final derivative at t=0, why not do it to all the partial...

If you have done this, then try the chain rule (http://en.wikipedia.org/wiki/Chain_rule) but use partial derivatives. if you have x(t) and y(t) then \frac{df}{dt} can be found by \frac{df}{dt}=\frac{\partial f}{\partial x}\frac{\partial x}{\partial t} + \frac{\partial f}{\partial...