Points Definition and 1000 Threads

Homework Statement How to find instantaneous acceleration when the velocity final is 4 m/s, the velocity initial is 1 m/s, the time final is 5 seconds, and the time initial is 2 seconds? Homework Equations The Attempt at a Solution I have no idea how to do the second derivative...

Hello all, I'm thinking about the following exercise from Intro to stoch. analysis: Let V be a continuous, nondecreasing function on \mathbb{R} and \Lambda its Lebesgue-Stieltjes measure. Say t is a point of strict increase for V if V(s) < V(t) < V(u) for all s<t and all u>t. Let I be the...

This is something that interested me after reading about time dilation. For the point of making it simpler, ignore relativity relating to gravitational fields Lets say for example, that the Earth does not orbit the sun, and the solar system doesn't orbit within the galaxy etc (makes it easier...

Homework Statement This doesn't seem like much more than a kinematics problem but it's for an upper division mechanics course so I chose to post it here. Feel free to move to intro if necessary. Homework Equations kinematics equations The Attempt at a Solution I focused...

Homework Statement Find the Cartesian Eqationn of the plane containing the points (0,-2,6), (1,8,-2) and (2,0,5). Homework Equations The Attempt at a Solution → OA = 0,-2,6 → AB = 1,10,8 → AC = 2,2,-1 Cross product of AB AC = 6,-15,-18 X - 0 * 6 Y - (-2)...

Say we take N random points in a volume V and connect the points pairwise with line-segments. I would like to estimate the number of segments that intersect some small volume v, and where N is large enough so that any small random sample volume v will have many intersections. Little volume v may...

Hi guys I'm helping my girlfriend with her Calc 1 homework and we seem to be stuck on this one problem. Am I missing something obvious? Homework Statement Homework Equations P = P_0 a^t \frac{5}{20} = \frac{P_0 a^1}{P_0 a^{-1}} \frac{1}{4} = a^2 a =...

A 180 degree circular arc (i.e. a half sphere) is obvious: When you rotate this about its two end points, you get a sphere. What about for something less than 180 degrees (e.g. 90)?: I believe this forms an ellipsoid, with coefficients a and b being equal, with respect to...

Hey guys, new here and this is my first post. Wondering if anyone could help me. So I've encountered a problem on Lagrange's undetermined multiplier. Usually i have no problem with these, but this one caught me off a little. g(x,y) = x^2 + y^2 - 4xy - 6 = 0 Find the points closest to the...

Homework Statement Just doing some review, and I keep getting the wrong answer. Can someone explain this for me please? The equation of the straight line through the points (-€2; 1) and (2; 3) is Book says the correct answer is 2y = x + 4 What are the steps to get 2y = x + 4 ...

Homework Statement 2. A solid copper sphere of radius 15.0 cm carries a charge of 40 nC. Find the electric field (i) 12.0 cm, (ii) 17.0 cm and (iii) 75 cm from the centre of the sphere. (iv) Explain how your answers would change if the sphere were hollow. Homework Equations...

I was reading a textbook on real analysis and came across this definition:Given a real sequence we say x is an accumulation point if given any \in greater than 0 we can find infinitely many natural numbers n such that |xn-x| is less than \in. I also found a theorem that stated if a real...

Why there is no interior points in a Cantor set? Please explain me in detail.

I wish to take up a discussion between Elroch and DrStupid in RossiUK’s topic “First Post – a question about Black Holes and Gravity”. My post is essentially an exposition of Elroch’s view, which I have shared for many years. Elroch’s exposition was very sedate, and I feel it needs to be shouted...

Homework Statement What is the potential difference between points a and b in the diagram? http://imgur.com/Ubr4A Homework Equations The Attempt at a Solution I have calculated the currents to be: I1=0.30A I2=0.65A I3=0.35A What I tried doing was (0.30*5) - 0.35= 1.15 V but...

I have a lattice plane in 3 dimensional space. Now, I want to cut it in a unit cell, but I have to write some code the make things get easier. As you can see from my figure, I can know the four coordinates of the highlighted atoms which form the boundaries of the top plane. My problem is if...

Homework Statement Find the inflection points and use second derivative test to determine where the function is concave up or down Homework Equations f(x) = (x - 1)/(x2 - 4) The Attempt at a Solution f'(x) = (-x2 + 2x - 4) / (x2 - 4)2 f''(x) = 2x3 - 6x2 +24x -8 / (x2-4)4...

Homework Statement Find the electric field strength at point P, which is located midway between charges A and B. The charges are separated by 20 cm. The first charge has a charge of 20 micro coulombs. The second charge has a charge of -30 micro coulombs. Homework Equations Electric...

I'm at a loss on this question...my troubles seem to be algebraic or that I'm simply missing something.x' = \mu - x2 +4x4 my method for these questions has basically been to do everything required to draw bifurcation diagram bar drawing the actual diagram itself (ie, find equilibria, what...

Homework Statement The problem as attached in the picture.The Attempt at a Solution So here's the problem that I was facing: G(t) has stationary points at t = 0, t = -1/2, t = -4 They correspond to (0,0), (a/4, -a) and (16a,-8a) in the function G(t). However, only (0,0) is a suitable...

I am struggling to find a way to count the number of irrational points defined recursively which satisfies specific conditions. This is the only hurdle I need to overcome, but the problem is proving itself extremely difficult. Here is my construction of a recursion. My goal is to...

I would like to find a way to get the intersection points of a circle and a sphere in 3d. The center of each and their radii are known. This needs to be a general solution so that I can move the center of the sphere in steps and find the intersection at each step. I am curious if this can be...

Hi, there are two material points with unitary mass that can move on a stright line. They are subject to a potential of mutual interaction V which depends on x and y and it's not symmetric, where x and y are the coordinates of the two points. I can choose in the istant 0 v1,v2,x and y. How...

Homework Statement Given a parametric eqn for the x,y coordinates , x(t),y(t) , how can i find the control points? Homework Equations de Casteljau's algorithm is used to compute the value for a given t given the control points. The Attempt at a Solution Control Points 0,3 are given...

Hello, I'm new here and I am not a physicist so please excuse any ignorance on my part. I am wondering if there are any ideas or theories involving the possibility of connecting two points within our universe and being able to see through or move between the two points. I am familiar with the...

I am trying to find out a method of determining the area below a curve. The end points of the curve are known in cartesian space, and the curvature of the curve is known. A diagram of the curve is here, shown in the images belowthis webpage [SIZE="1"]ß must be in radians...

Hello all, I am having an issue with the splot command in gnuplot. The format of the data I am trying to plot is shown below: 3.09411 71.75663 -2.17624 3.09238 67.64099 -1.94456 3.10106 73.70542 -2.85122 3.09494 75.71568 -3.49932 3.09846 75.29150 -1.14593 My...

Hello everyone! I just finishexd reading Death By Black Hole and I was interested in the Lagrange points. Neil talks about how if you placed objects inside of them you could use the points as place holders for objects while building in space. I couldn't seem to find anything about the width of...

How to Find the points on curve which are nearest to origin

[FONT=Georgia]I have two circles with the same radius and I want to calculate the points of tangency. [FONT=Georgia]For example, in the picture below, I want to calculate...

This might be more of an algorithm question than a math question: how do I go about distributing n points as evenly as possible in a 3D volume of non-basic shape? Think human organs or the like. A related question is how do you know when you're inside a 3D volume versus outside it? Thanks!

Homework Statement Determine the location and type of all critical points of the given equations and sketch the phase portrait y"+cosy=0 The Attempt at a Solution I've done some like this before but they were all systems of equations. I'm actually not sure how to do the...

I'm trying to teach myself optics from Frances Sears' book Optics from 1949. I'm attempting every problem, and there are answers to the odd ones in the back. I've gotten a lot of wrong answers and don't know why, had a few I just couldn't even see how to start, and at this point, I'm seeing...

Homework Statement I was wondering if you could help me on how to draw these on a graph (4, 0°) and (3, 27°) The Attempt at a Solution Just a hint, Please

I couldn't get these lines from my book. I will reproduce it here. Warning: In step 1, if you use computer to fit a polynomial to the data , it could lead to disaster. For example, consider fitting a sixth degree polynomial to the seven data points, or, an (n-1) degree polynomial to n...

Homework Statement The line that is normal to the curve x2+2xy-3y2=0 at (5,5) intersects the curve at what other point? 2. The attempt at a solution I differentiated the equation, found the slope of the curve at that point, and I then found the equations for the tangent line and normal...

So I am solving for the critical points of x3-3x-y2+9y+z2 I've found the critical points and I'm just evaluating them in the Hessain. Now I computed the eigenvalues for the hessian, but one of my 2nd order derivatives was a constant. So my hessian looked like this (it was diagonal, so I'm...

What is the mathematical equation or algorithm for alignment of four points in cartesian coordinates (X & Y). Say, we have 4 nominal points (Xn & Yn), and another 4 measured points (Xm & Ym)?. After alignment, what are the new locations of the measured points (Xmn & Ymn)?.

Hi, I have faced the following question. In our lab we perform different measurements on Transistors. We program a scope and that controls the tests. For one of our tests we would like to calculate the total charge Q. Mathematically this is given by Q=∫ dt i(t), where i(t) is given by i(t)...

I have the equation (x^2)/(sqrt(x+1)) This one has been stumping me, not sure how to reduce the derivative properly much less solve for 0. I get it down to this using the quotient rule: ((x+1)^(1/2)*2x - x^2*1/2(x+1)^(-1/2)) / (x+1) Just started learning derivative a few weeks ago...

Fitting points to "skewed" sinusoids Hello, I have a problem related to least square fit of data. Let me start from a step back. I have a set of points, given as x-y coordinates. x represents an angle and y the corresponding value of a function. I am fitting sinusoids to those data points...

Hello, I'm trying to find a good reference for how to find or calculate or know which points in the Brillioun zone are "TRIM" (time reversal invariant momentum) points? If anyone is familiar with this topic and could perhaps post a reference or two it would be of great help. Thanks!

Why is the electric field strong in sharp points?? There is a question in my book regarding the intensity of the electric field near a sharp surface in a conductor. There is a hint which says that it will be helpful to examine the field lines near those sharp surfaces. This is from my...

Let f(x,y) = x^2 y - xy = x(x-1)y be a polynomial in k[x,y]. I am looking for the singular subset of this function. Taking the partials, we obtain f_x = 2xy - y f_y = x^2 - x. In order to find the singular subset, both partials (with respect to x and with respect to y) must vanish. So...

Homework Statement Basically I found the following system of DE's: \frac{dx}{dt}=y \frac{dy}{dt}=-\frac{g}{l} \sin x - \frac{cy}{ml}. (Damped pendulum) I'm asked to analize the stability of the critical points x=0, y=0 and x=\pi, y=0. Using intuition the first point is asymptotically stable...

Hi all! I need help..:) I need to model the dynamic of this system: I'm in the plane (2-dimensions). There are two points (with m1 and m2 masses) free to move with different speed vectors (in module and direction). At some point, when the distance between them is d, the two points...

Homework Statement Find a parametrization of the equation of the line formed by the points A, B, and P. A(2,-1,3) B(4,3,1) P(3,1,2)Homework Equations x=x_0+v_1*t y=y_0+v_2*t z=z_0+v_3*tThe Attempt at a Solution Alright, so, I've already determined that P is equidistant from the points A and...

1st part of Exercise #27 is: Define a point p in a metric space X to be a condensation point of a set E in X if every neighborhood of p contains uncountably many points of E. Suppose E is in R^k, E is uncountable and let P be the set of all condensation points of E. Prove P is perfect...

Homework Statement Plot the Following points(given in polar coordinates). Find all the polar coordinates of each point. a. (2, pi/2) b. (2,0) c. (-2, pi/2) d. (-2,0) Homework Equations none The Attempt at a Solution I have plotted it on a graph but could someone explain to me...

what creates the "star points" in telescope pictures of stars? it's a basic question. e.g. see this hi-rez Hubble Deep Space pic: http://upload.wikimedia.org/wikipedia/commons/9/9b/Hs-2004-07-a-full_jpgNR.jpg i count about three bright objects with pointy cross-like projections from...