Points Definition and 1000 Threads

Homework Statement https://scontent-b-dfw.xx.fbcdn.net/hphotos-prn1/v/1012733_10201076259690370_236735593_n.jpg?oh=4896ca67a34d3b223b764aba8ed308ab&oe=528A1B57 Homework Equations http://upload.wikimedia.org/wikipedia/commons/3/34/Phase-diag2.svg The Attempt at a Solution Not sure entirely...

For the following example:(if possible give example or just state impossible 1) a bounded subset A of R for which sup A is not a limit point of A. An example is (0,1) union {7}. will this work? 2) a finite subset A of R that is not closed I think it is not possible. Please give some hints...

Homework Statement i had some problem with MATLAB of how to create two points of random positions and adding another few random pointsHomework Equations how to create the points, set a point as the centre, make the iteration for one point to rotate the centre and also the other iterations for...

Homework Statement The aqueous solution with the lowest freezing point of the following group is: 1) 0.01m MgSO4 2) 0.01m NaCl 3) 0.01m CH3CH2OH 4) 0.008m MgCl2 5) all equal Homework Equations Solutions have lower freezing points and higher boiling points than their solvents...

In the textbook I am working with, an isolated point of A is defined to be a point X in A such that there exists a neighborhood (open ε-ball) centered on X containing no point in A other than X itself. A boundary point of A (which need not be in A) is defined as a point X in A such that...

Hi Why are displacements calculated on integration points but not directly over the nodes. The whole purpose of discretizing a structure in FEA is to have fewer degrees of freedom, then why add integration points when there are well defined nodes. Also, can somebody please explain having...

In Dummit and Foote Chapter 15, Section 15.3: Radicals and Affine Varieties on page 679 we find the following definition of affine variety: (see attachment) ------------------------------------------------------------------------------------------------------------------------------------...

In Dummit and Foote Chapter 15, Section 15.3: Radicals and Affine Varieties on page 679 we find the following definition of affine variety: (see attachment) ------------------------------------------------------------------------------------------------------------------------------------...

Homework Statement Suppose that a continuous function f(x) has horizontal tangent lines at x = -1, x = 0, and x = 1. If f"(x) = 60x^3 - 30x, then which of the following statements is/are true? A) f(x) has a local max at x = 1 B) f(x) has a local min at x = -1 C) f(x) has an inflection...

Homework Statement A 100 nC point charge is located at A(-1, 1, 3) in free space. (a) Find the locus of all point P(x,y,z) at which E_x = \frac{V}{m}. Find y_1 if P(-2,y_1,3) lies on that locus. Homework Equations...

Hi there , I have some simple (on 1st look) questions. I just need some help.http://img59.imageshack.us/img59/3018/5hby.png 1st question. I think the expected value should be 150 since the probability of getting a head is 1/2 .. 300x1/2 = 150 so the mean should also be 150. the variance...

Hello there, I hope I'm posting in the right section. I have been doing some work on evolutionary game theory and poker. I will give a brief description of how I got here. I have eight strategies i = 1, 2, \ldots, 8 and the eight proportions of the population playing each strategy is...

Homework Statement The equation of motion of a particle moving in a straight line is ##x'' - x + 2x^3 = 0## and ##x = \frac{1}{\sqrt{2}}, x' = u > 0## at ##t = 0##. Identify the singular points in the phase plane and sketch the phase trajectories. Describe the possible motions of the...

Homework Statement *)Given two points A=(4,3,2) and B=(-2,0,5).Find the unit vector extending from origin toward the midpoint of line AB Homework Equations The Attempt at a Solution Direction vector to AB=(-6,-3,3) and hence direction vector to its midpoint is (-3,-1.5,1.5)...

Homework Statement Find the equilibrium points of the system, determine their type and sketch the phase portrait. ##\frac{dx}{dt} = -3y + xy - 10, \frac{dy}{dt} = y^2 - x^2## The attempt at a solution Putting it together: ##\frac{dy}{dx} = \frac{y^2 - x^2}{-3y + xy - 10} \equiv...

Hallo all... I have a couple of plot values that I am trying to derive a formula from. The points are almost linear but not quite... Was hoping someone could shed some light on how to go about this... I have Matlab 7.1, would like to use it if at all possible... Any help would be...

if A is a subset of B and the frontier of B is a subset of A then A=B. I am pretty sure that this is true as I drew I diagram and I think this helped. A frontier point has a sequence in the set and a sequence in the compliment that both converge to the same limit. However I'm not really...

How would I go about proving that if A is a subset of B then the interior points of A are a subset of the interior points of B?

Background: I've derived the equation of motion of the bead shown in the picture below using the Lagrangian \omega^2Rsin(\theta)+r\ddot{\theta}=0 The equilibrium points are at θ=0 and π. I'm now to show that only one of these points is stable. Homework Statement Show that only one of the...

Hello! First of all, thank you for your time in reading my post. Secondly, I am not looking for people to freely give me the answers. With all that said... Homework Statement I have a test point randomly selected on a graph, but what I am trying to figure out is where on this graph...

3.4. Let E\in  R. Prove or disprove the following statements: (i) if a\inE and b\inE^{c} = ℝ\E and a < b then [a ,b] \cap∂E IS NOT EQUAL TO ∅. (ii) if a\inE and b\inE^{c} = ℝ\E and a < b then (a ,b) \cap∂E IS NOT EQUAL TO ∅. I am really stuck I know that the frontier of a set is when a...

How do you find the interior points of a subset? I understand that a point is an interior point if there exists an epsilon neighborhood that is in the set, but I don't know how that would work with specific sets. Any hints?

Homework Statement Find the Möbius transformation that maps 0 -> -1 1 -> infinity infinity -> 1 Homework Equations w = f(z) = \frac{az + b}{cz+d} The Attempt at a Solution My first idea was to attempt to solve it as a normal system of eq's but that quickly falls apart due to...

Definition: A subset $D$ of $\mathbb R$ is said to be discrete if for every $x\in D$ there exists $\epsilon>0$ such that $(x-\epsilon,x+\epsilon)\cap D=\{x\}$. Question: Does there exist a discrete subset $D$ of $\mathbb R$ such that the set of limit points of $D$ is an uncountable set. ___...

Hello MHB,This is an old exam I got a question, Decide all stationary points to function f(x,y)=x^3y^3 under constraint x^3+y^3+6xy=8So basicly this is how they Solved it and I did so as well but I Also have learned that there is stationary point where gardient of constraint is equal to zero I...

Tell me if I am correct: The wave part of wave-particle duality is a probability wave. An electron, for example, is always a 0 dimensional point (as far as we know), and the wave characteristic of the electron determines the possible locations of the electron and probability of finding it in...

Hello, Suppose I have a primitive cubic cell with 8 atoms, one on each corner of the cube. I don't understand how this consists of only one lattice point? Doesn't each corner have a lattice point, thus the cell would consist of 8 lattice points??

Hi, I've seen pictures like this one: http://www.lcst-cn.org/Solid%20State%20Physics/Ch25.files/image002.gif Is there any good explanation somewhere on this subject? I'm using Kittel's book but there's nothing in there on this.

hey folks, I am making a program that uses object tracking to watch a juggling pattern and plays notes based on the peaks of the balls. I want to predict when/where(x,y) a peak will happen before it does and what i have to work with is when/where(x,y) the ball appears in each frame. I have...

Homework Statement Find the potential inside and outside a uniformly charged solid sphere of radius R and total charge q. Homework Equations V(r) = -∫E dl The Attempt at a Solution I just have a question about finding the potential inside the sphere. Why integrate from infinity...

Homework Statement f(x,y)= 3x5y2 - 30x3y2 + 60xy2 +150 How do I find the critical points where this equation equals zero? Homework Equations None? The Attempt at a Solution I found the partial derivatives, but I'm stuck now and don't know where to go from here. dx = 15x4y2...

Find all starionary points to function f(x,y,z)=x^2+xy^2+yz^2-2z and Also decide it character. I find a point at (-1/2,1,1) now I have to check if it is semidefinit etc.. But I only know the formula for 2 variable Q(h,k) I try search this method in My book and can't find it.. What you call this...

Homework Statement What are the bifurcation values for the equation: dy/dt = y^3 +ay^2 Homework Equations The Attempt at a Solution Equilibrium solutions: y^3 + ay^2 = 0 ==> y^2 (y + a) = 0 ==> y = 0 (double root), or y = -a. a = 0 is the sole bifurcation point, since...

Homework Statement Which of these three points falls on the line? l: r(t)=(i+2j)+t(6i+j-5k) P(1,2,0); Q(-5,1,5); R(-4,2,5) I have the answer, but I don't understand why P and Q fall on the line but R does not. Is it because the i and j magnitudes are different for R?Homework EquationsThe...

Homework Statement Arrange compunds in order of increasing boiling points and explain why. C2Br6,C2F6,C2I6,C2Cl6 Homework Equations The Attempt at a Solution I have C2Cl6 < C2Br6 < C2I6 < C2F6 My explanation is as follows. C2F6 is highest because it has dipole dipole forces...

Homework Statement Suppose (a,b) and (c,d) are unique points in ##\mathbb{R}^{2}## that satisfy Ax+By+C=0. Suppose also that the solutions of Ax+By+C=0 form a line. Then the line that (a,b) and (c,d) lie on is unique.Homework Equations I showed in a previous part of the problem that there...

Homework Statement Consider the function f(x,y) = (x2 + 4y2)e(1-x2-y2) Find all critical points, and identify them as maxima, minima, or saddle points. The Attempt at a Solution I took the partial of x and the partial of y, and set them equal to 0. This is what I got: fx(x,y) =...

Homework Statement Find an expression for a cubic function f if f(1)=6 and f(-1)=f(0)=f(2)=0 Homework Equations I figured it out but I am not sure why we use the equation f(x) = a[x-(-1)](x-0)(x-2) The Attempt at a Solution Im assuming its because if u times that equation that is a...

I have a complicated 3d nonlinear differential system which I solve algebraically using maple's solve command. I aim to find the equilibrium points of the system using MAPLE and then plot these equilibrium points as a function of the 3 parameters alpha,beta,gamma(a.k.a.bifurcation diagram). The...

Why Mild Steel has two Yield Points ? :confused:

Hey guys, I'm just pondering a beam problem fir a structure that I'm analysing. It appears statically indeterminate to me? The beam is bolted to a support at locations A,B & C. There are two point loads between span B-C. There are no symmetrical distances or support locations etc. Initially...

Homework Statement Find the shortest distance between two points using polar coordinates, ie, using them as a line element: ds^2 = dr^2 + r^2 dθ^2Homework Equations For an integral I = ∫f Euler-Lagrange Eq must hold df/dθ - d/dr(df/dθ') = 0 The Attempt at a Solution f = ds = √(1 + (r *...

Is there already a solution to this available somewhere? Am I not googling it right? I did come upon solutions for this with a point and plane defined by way of vectors and normals but not points. Have I stumbled upon a blank I can fill? Is there room here for a math paper? My approach is...

Basically I don't know anyone in real life that can help me with this, so I need help checking to see if my answers are correct :) PART A 1) Using a graphing utility solve the following system of linear equations. Round your answer to the nearest hundredth. y = -4x+2 x - 2y = 10 My answer: x...

What will be the electric field at the points p3 and p4 in the attached image. I think at p3 it will be zero as it is inside the conducting surface But what about p4?? Will it be zero too? Due to negative and positive charges or will it be sigma/E(sub)o(/sub).. And why?

Homework Statement Find all singular points of xy"+(1-x)y'+xy=0 and determine whether each one is regular or irregular. Homework Equations The answer is x=0, regular. The Attempt at a Solution I know that x=0 since you set whatever is in front of y" to 0 and you solve for x, right...

Help! Using 3 Points to Find Quadratic Equation in General Form I have a quadratic equation question that I have to solve, but I can't seem to understand it. The question is: "Using points (1,0);(3,0);(0,-6), find the quadratic formula in General Form (ax^2 + bx + c). My teacher says...

I'm doing this in Matlab but it's not restricted to any particular software. I have a bunch of geographical points (x,y coordinates for each) and I want to take all the points that are 50 km or closer to the reference point. I took the great-circle equation to convert geographical longitude...

Homework Statement 1. (a) Find the equation of the circle with the straight line joining A(1;-1) and C(3; 4) as diameter. (b) Hence or otherwise, derive the general formula (x - x1)(x - x2) + (y - y1)(y - y2)=0 of the equation of a circle for the points A(x1; y1) and C(x2; y2): Homework...

Homework Statement I am trying to figure out how to solve for problems that give a function and ask for the critical points. However, the ones I am having difficulty with are the ones that have multiple trigonometric functions included in them.Homework Equations Find the critical points of the...