# Search results

1. ### LaTeX Particular environment LaTeX help

Hey all! I'm trying to learn \LaTeX, and so far I'm doing fine. However, I would like to know if it is possible to be able to find out if a particular environment is in use at a certain point. Basically, I was wondering if something like: \isInUse{math} exists in LaTeX. Does anyone...
2. ### MATLAB Matrix of ODE's in MATLAB

Hey all, Consider the system X' = f(X), where X is a square matrix. I would like to solve this system with MATLAB, but all of its solvers require X to be a column vector. Of course, it would be possible to rewrite X' and f(X) as column vectors, but I guess some efficiency would be lost. It...
3. ### MATLAB (MATLAB) Ignoring output arguments

Hey all, Suppose I have a MATLAB function that returns two (or more) output arguments, but I only care about the second one, and I do not wish to assign the value of the first one to a variable. What bugs me is when, for example, I solve an ODE: [t, x] = ode45(blablabla) and then...
4. ### Fourier transform -> power spectrum

Fourier transform --> power spectrum Hey all! I've been learning about the discrete Fourier transform (and FFT too) recently. What I don't understand is why applying it to a signal gives its power spectrum. I am not really good in physics, so to me it just seems like a magical formulae, one...
5. ### I love geometry

I love geometry :) Hey all! This is one problem I haven't been able to solve. I've had a class on theorems relative to circles and triangles but I still can't figure this one out. 3 identical, equilateral triangles are placed as seen on the attachment. Their sides measure 28cm, and the...
6. ### Maple Maple, anyone?

Hey all, I'm having trouble setting initial conditions when solving differential equations in Maple. Here's the equation: \theta(t)''+4\pi^2 sin(\theta(t))=0, with \theta(0)=A and \theta'(0)=B as initial conditions. I'd like to solve it with a command like...
7. ### Simple pendulum help

Hey all, I'm a math students, and I've got physics homeworks to do, and... I need some help :smile: To make it short, I solved the approximation of the differential equation of the angle of a pendulum in function of time, and I got this...
8. ### A little geometry

Hi all, I'm having a hard time proving something. Let's say you have a triangle with a 90° angle. How can I prove that the lenght of the segment between the middle of the hypotenuse and the 90° angle is half the lenght of the hypotenuse itself? Here's a little pic to help you... Thanks...