Recent content by Aikon

Hi all, It is really a history question. I read that Galileu developed the concept of inertia, but today I knew it from Newton's 1st law. So my question is: Both of them arrived at the idea independently? Was Newton aware about Galileu's work and used the law because it is the basis for his...

Yeah, i got it...it is easier to use table of integrals. it gives the expected <x>=\frac{a}{2} for any value of n. thanks

Ok...this must sound stupid, because i didn't found answer on the web and on my books...but i am having trouble with the infinite square well. I want to calculate <x>. V(x)=0 for 0<=x<=a <x>=\frac{2}{a}\int^{a}_{0} x \sin^2(\frac{n\pi}{a}x)dx Doing integration by parts i got to...

Great remark...You are right...Thanks a lot! Just one thing...I said that i got to the answer...It was a year ago and was a multiple choice question that had answers in the book. Maybe the book was with the wrong answer!

This is the problem that a teacher (Kevi Spacey actually) presented the class on the movie 21: You are on a TV show and the announcer asks you to choose 1 from 3 doors. Behind 2 doors there are a goat and behind 1 there is a new car. The guy coose door 1. The announcer go and opens door 3...

Hi, I am trying to show the reader what is the main diagonal of a matrix, so i wrote the code using the xy-pic package, this is the code: \begin{displaymath} \left( \xymatrix @=0.5pc { a \ar@{-}[dr] & b\\ c & d\\ } \right) \end{displaymath} In the compiled file the parenthesis...

:) Thanks. It is very nice to listen a good feedback, Actually, there is a bug if you enter a system with different number of equations and variables. Maybe I fix it in the future.

Yes, you got it. It is a simple program, so I didn't atached a public license.

Hi, I made this program in java, take a look: https://github.com/BetoKahn/Gauss For the english version I didn't uploaded the code, only the runnable .jar file. For the portuguese speakers you can see the code. I hope you enjoy,

Hi Kurtz, Thanks, I will read the article later, it appears to be whatI need. It is because of people like you that I love this forum. See you,

Hi all, I want to convert a curve from polar coordinates function to a parametric function. The function is: r = 2 \cdot \cos( 4\cdot\theta ) I want to convert this for ( x(t), Y(t) ). Why do I want this? Because I saw that wxMaxima make plots of parametric functions, but I don't know...

Thank you, After i read your reply i went back to check the exercise and i noticed that the sistem is in equilibrium ! I need to be a little more attentive to the details. it is really just a "simple Newtonian mechanics problem".

Homework Statement It is the review problem on p.131 of Physics for scientists and engineers ( Serway, 4th edition). It is the classical problem of 2 blocks in an incline(with angle \theta) with masses 2m and m (in order from bottom to the top of the incline) and 1 block suspended trough a...

Homework Statement This problem is in Introduction to Eletrodynamics, of Griffiths, 3rd edition, p.20, problem 1.19. He asks a vector function v(x,y,z), other than the constant, that has: \nabla\cdot\vec{v}=0 \mbox{ and } \nabla\times\vec{v}=0 Homework Equations I hope you know them...

Thank you all the answers. I liked this: With this identity it becomes almost trivial, because (sin210 +sin280)=1 and it goes like this for other pairs, it gives 5 in the end.