Regular Definition and 269 Threads

Hi all, this has been bugging me so maybe you can help me out. In the front window of my house, there is a dent in the glass that looks somewhat similar to this: http://www.flickr.com/photos/guerra/2557095422/" However, there is not hole in the glass. But the shape of the dent is...

So is there any set of defined rules that help in the simplification of regular expressions? Because till now I would simply try and look at the patterns and see whether this or that simplified version would generate the same.Intuitive, but now always fast or correcct. So is there any...

Homework Statement To prove that every metric space is regular. :) The Attempt at a Solution So, a regular space satisfies the T1 and T3-axioms. For T1: Let a, b be two distinct points of a metric space (X, d). Then d(a, b) > 0, and let r = d(a, b)/2. Then the open ball K(a, r) is a...

hey i am stuck on this question for my ode course its using frobunius 4. show that the equation yii + 1/x yi + (1-1/(4*x^2))y = 0 has a regual point at x=0 using the method of frobenius assuming a solution of the form y=\sum ar xc+r show that the idical equation is c^2=1/4...

Homework Statement Σ = {a,b} find regular expression for 1)all strings that haven't got more than 3 a's 2)all strings that have a number of a's that is divisible by 3 3)all strings that have the substring aaa only one time The Attempt at a Solution 1) b*Ub*ab*Ub*ab*ab*Ub*ab*ab*ab* 2)...

Homework Statement [PLAIN]http://img265.imageshack.us/img265/6778/complex.png I did the coefficient of the w' term. What about the w term? This seems like a fairly standard thing, but I can't seem to find it anywhere. What ansatz should I use for q, if the eqn is written w''+pw'+qw...

Homework Statement 6x2(x+1)2y''+0.5x(x+2)y'+y=0 ii) Find all values of r for which there is a series solution of form xr\sum(anxn,n=0,inf) a0 \neq0 Find all values of r for which there is a series solution of form inf xr\suman(x-2)n...

Hey, I'm in second year of engineering, and have to pick my courses for third year. I have the option of going into mechatronics or stick to regular mechanical engineering.I don't know what i should do. I heard mechatronics has a lot to do with controls system. I want to invent my own things...

My school has a regular 4 year physics major and another 4 year 'Honors' major. There is a more stringent selection of electives and I think it is more in depth in general. I assume it would be a good idea for me to do it but I'm just curious if the decision would have any bearing on grad school...

I am planning to take the A.P. Physics exam B at the end of the school year. My question is, will this be ridiculously difficult for me? In my regular physics class, we have quite a slow pace on moving forward (We're only on centripital force!). How much will I need to know in order to pass the...

ODE Series Solution Near Regular Singular Point, x^2*y term? (fixed post body) Homework Statement Find the series solution (x > 0) corresponding to the larger root of the indicial equation. 5x^{2}y'' + 4xy' + 10x^{2}y = 0 Homework Equations Solution form: y =...

I was wondering, since the size of complementary sets comes up often in other areas of math, e.g. the set of rational numbers is countably infinite but set of irrationals is uncountably infinite, so that the set of irrationals is in some sense "larger" than rationals. Does a similar kind of...

how to prove that the symmetry group of a regular polygon has only 1 and 2 dim irreducible representations?

I have to learn a section from my textbook and I can't seem to undertand what a regular transition matrix is. The definition given is: A transition matrix is regular if some integer power of it has all positive entries. Now an identity matrix isn't regular, but I am pretty sure all integer...

what happens if u accidentally use regular water to dissolve something u want to electrodeposit later instead of using DI water? will it change how it normally works? i think i mixed up the jars :frown:.

Recently, I purchased a pair of glasses from a privately owned optic store. I specifically asked for hi-index lens (1.56 or 1.60, I am not sure). The lens I got, however, is kind of thick (around 5 mm thick on the edges).My eye -sight is poor though, -5.00 sphere, -1.25 cylinder on the worst...

Hello, I am trying to understand the definition of regular point, regular singular point and irregular point for example, the ode. what would be the r,rs or i points of this? x^3y'''(x)+3x^2y''(x)+4xy(x)=0 dividing gives the standard form y''+(3/x)y' + (4/x^2)y=0 So...

I am currently studying a great text Elementary Differential Equations and Boundary Valued Problems 9th edition; and we have come to chapter 5 and are studying Ordinary Points, Singular Points, and Irregular Points. (get the point?) Anyway, I did see these mentioned,, this...

Homework Statement A floor tile has the shape of a regular polygon. If the tile is removed from the floor and rotated through 50◦ it will fit back exactly into its original place in the floor. The least number of sides that the polygon can have is? I don't know what are the theories that i...

I am thinking about doing Honors Physics. Is getting the major in math as well a good idea?

Homework Statement α(t) = (sint, cost + ln tan t/2) for α: (0:π) -> R2 Show that α is a smooth, parametrized curve, which is regular except for t = π/2 The Attempt at a Solution I am familiar with the definitions of smooth and regular, which I have provided below, however I am...

I'm trying to create an rss feed from a html table on the main page of a web forum. I want to do this because the table displays the new posts. I use yahoo pipes and you can see my attempt here: http://pipes.yahoo.com/pipes/pipe.info?_id=0e72fee43090386fddbc9191f5cddc86 The pipes work up...

Homework Statement Let X by a completely regular space and let A and B be closed, disjoint subsets of X. Prove that if A is compact, then there is a continuous function f : X --> [0,1] such that f(A) = {0} and f(B) = {1}. The attempt at a solution Let {U} be an open covering of A, U_1...

Hi, I read the following theorem in a book: If {A_n} is a sequence of nowhere dense sets in a complete metric space X, then there exists a point in X which is not in any of the A_n's. But what if I say X={1,1/2,1/3, ...} \cup {0} with the regular metric d(x,y)=|x-y|, and A_n={1/n,0}. Why...

A "concentration" degree vs a "regular" degree Good afternoon everyone. I'm new here and it's great to be here. I have a very large interest in Physics and plan on getting a degree in said field. I do have one big question; Is there a big difference between having a BS in Physics and a BS in...

Help: Perpendicular project is regular surface?? (edit found a better way of showing this) Homework Statement Hi I have this problem here which is causing me trouble. Show that the perpendicular projection of the center (0,0,0) of the ellipsoid \frac{x^2}{a^2} + \frac{y^2}{b^2}...

Prove that subset of regular surface is also a regular surface(updated) Dear Sirs and Madam's I have following problem which I hope you go assist me in. I have been recommended this forum because I heard its the best place with the best science experts in the world. Anyway the problem...

What is the general solution of x^2y''+xy'-y=0 i tried a series solution y=\sum_{n=0}^{\infty} a_n x^n and whitteld it down to \sum_{n=0}^{\infty} (n^2-1) a_n x^n=0 but this isn't getting me anywhere secondly how do i show that x=0 is a regular point of...

How many decibels does a regular apartment wall cancel out?

Hi: This problem should be relatively simple, but I have been going in circles, without figuring out a solution: If f:X->R^2k is an immersion and a is a regular value for the differential map F_*: T(X) -> R^2k, where F(x,v) = df_x(v). Then show F^-1 (a) is a finite set...

Homework Statement Given a parameterized curve \alpha:(a,b)\rightarrow \mathbb{R}^2, show that this curve is regular except at t = a. Homework Equations I know that according to the defintion that a parameterized curve \alpha: I \rightarrow \mathbb{R}^3 is said to be regular if...

Through my learning of calculus, I have come under the impression that there is an important difference between the derivative of a variable with respect to another, and the partial derivative of a variable with respect to another. For example: I think that \frac{dy^2}{dx} = 2y\frac{dy}{dx}...

Homework Statement What is an algorithm which decides whether a context-free language is actually a subset of a regular language? That is, given CFL and RL, how do we decide whether CFL is a subset of RL?

Hello, firstly, what does the regular expression "\\+" do? Would that literally match up "\+". Could I possibly get some recommendations on some software to try regular expressions with as well actually please? and secondly, I've been fiddling around with the cacls command and I've noticed...

Homework Statement I have this pole with mass M and length L which is on a flat table with no friction. Another particle, which has the same mass M hits him on its edge with velocity V, which is vertical to the pole. then, the particle sticks to the pole and they move together. I need to...

Is there an algorithm for converting DFA (or NFA) into regular expressions?

Hello guys, I just bought TI-Nspire CAS+ graphing calculator, and I am wondering what are the differences between CAS+ and normal CAS. What are pros and cons? Thanks in advance, Jan

The two dimensional regular polygon series, the triangle, square, square, pentagon etc. is infinite. If for some reason, it was finite, what would our universe become? especially the dimensions of length and breadth.

Suddenly I'm curious what other uni physics students do and I am studying the physics curriculum of another local uni just now, but it seems there're a lot of differences between the two top uni here...we took a-level here so it's a 3-year program. The core courses are: 1 year on some...

Homework Statement A regular hexagon with center at the origin in the complex plane has opposite pairs of sides one unit apart. One pair of sides is parallel to the imaginary axis. Let R be the region outside the hexagon, and let S = \{ 1/z |x \in R} . Then the area of S has the form a \pi...

And, just a few minutes ago, I realized I forgot to square a constant in solving for rho in spherical coordinates in determining the limits of integration for a triple integral. I got cosine of phi as 1/2, which gives phi as pi/6, but since I forgot to square the two, it actually is pi/4. :mad...

For solving a series solution near a regular singular point with the Frobenius method, why is it that the indices of summation derivatives aren't shifted? For example, in my textbook and lecture notes y = \sumA_{}nx^{}n+r from n=0 to infinity y' = \sum(n+r)A_{}nx^{}n+r-1 from n=0 to...

I have a prescription for Wellbutrin, a drug which blocks reuptake of dopamine (strong) and noradrenaline (weak). I got this prescription because my family wasn't keen on my idea of self-medicating with ephedrine (strong noradrenaline response) and caffeine (strong dopamine response). I was very...

1) A vector form of Green's theorem states that under certain conditions, where n is the unit outward normal to the curve C and D is the region enclosed by C [Now, my question is: must n be a unit vector? Why or why not?] 2) A "regular region" is a compact set S in Rn that is the...

Problem on regular language! Homework Statement Homework Equations The Attempt at a Solution Thanks!

So i began reading up on some group theory and I came across an interesting question, what is the order of the group of symmetries on of a n-sided regular polygon? with a square it's 8, triangle it's 4. I feel like I'm missing something with the pentagon because I'm only finding these: the 5...

Homework Statement Balance this redox equation. Homework Equations Ag + H^{+} + NO_{3} ^{-} \rightarrow Ag^{+} + H_{2}O + NO The Attempt at a Solution Using a conventional balancing mechanism I got these coefficients: 1 + 8 + 2 -> 1 + 4 + 2 but the correct...

I am trying to remember the rumor I heard about a new gun shooting design in one of my ap physics class discussions, do you guys now of any new breakthrough designs? anyway i think it has to do with the reloading mechanism. (I know I have asked a question of this type before, so if i sound...

When integrating and differentiating I'm not sure weather to use a lower case delta or just a d. Is there a time when one is more a appropriate then another or does it not even make a difference? Are they to completely different things? I know it might seem trivial but I have no idea which is...

Superimpose concentric regular polygons of equal area with maximal symmetry, starting with the equilateral triangle and sequentually approaching the circumference of a circle. What series can you derive for the fraction of the area not occupied by any successive polygons?