Square Definition and 1000 Threads

Homework Statement compute f'(x) using the limit definition. f(x) = \sqrt{x} Homework Equations f'(x) = \stackrel{lim}{h→0} \frac{f(x+h)-f(x)}{h} The Attempt at a Solution Plugging in the function values gives you f'(x) = \stackrel{lim}{h→0} \frac{\sqrt{(x+h)}-\sqrt{x}}{h}...

If at 120 K the Vrms is v , then at 480 K it will be a. 1 b. 2 c. 3 d. 4 Which formula is to be used here? Plz solve this.

Homework Statement 4. Implement a simple method to find the square root of a double precision floating point number x. A simple method is to consider the error produced by a “guess” y of the solution. Square the value y and compare with the value x. If y is correct, the error e=|y2-x| where ||...

Homework Statement Use the boundary conditions to show that \frac{A+B}{A-B}=\frac{k_1}{k_2}\frac{C+D}{C-D}=\frac{k^2_1}{k^2_2} Homework Equations A+B=C+D and k_{1}A- k_{1}B = k_{2}C- k_{2}D C e^{i k_{2}L}+D e^{- ik_{2}L} = F e^{i k_{1}L} and k_{2}C e^{ ik_{2}L}- k_{2}D e^{-i...

Lets define trace for each square matrix A its trace as sum of its diagonal elements, so tr_{n}(A)=\sum_{j=1}^{n}a_{j,j}. Now proove that trace is a linear functional for all square matrix. I would be happy to know what has to be true for anything to be a linear functional? If I...

I feel kind of ridiculous making this post, but here we go: What would be the correct answer to this question; Choose all the number sets (natural, integer, rational, or irrational were the only options given) that -√81 belongs to, and show how you found your answer. What I said was this...

Homework Statement http://img842.imageshack.us/img842/4917/physp6.jpg I am trying to solve the above problem. However, I am supposed to solve it with the following values: U=54.7eV L=0.2nm Particle is an electron, so: m=9.109E-13kg=0.511eV/c^2 Essentially I am supposed to...

Fair to say there are "twice" as many square matrices as rectangular? Is it fair to say that there are at least twice as many square matrices as there are rectangular? I was thinking something like this... Let R be a rectangular matrix with m rows and n columns, and suppose either m < n...

Homework Statement Alpha=0.91 ,beta=2.92, T0=0.91 Homework Equations The value of a0 for the square waveform The Attempt at a Solution 1/T0 * area = 1/0.91*(2.92-0.91)*0.91

Hi Everyone, For an individual inquiry and formal lab report task at school I have chosen to conduct an experiment to find out whether hot shoe mounted flash units follow the inverse square law and how the flash zoom is affected by the inverse square law. My first question is that In order...

Homework Statement What is the percentage of power (out of the total power) contained up to the third harmonic (power in DC component, a1 , a-1 , a2 , a-2 , a3 , a-3 ) of the square waveform shown above? (the duty cycle = D = τ/T0= 0.5) Homework EquationsThe Attempt at a Solution Hey all...

[SOLVED]Trig problem: max square cut from circle Since this one is homework related, ill ask this as a procession so that I can make sure that I am grasping the logic. the question is that with a round log with a diameter of 16cm, what is the strongest log that can be cut where the strength =...

Is there any method to find the exact value of the square root of 3,5,7,11,13,14,15,17,18, etc.? Thank you

Hello PF members, I want to solve this integral but I cannot find a method. \int\sqrt{1 - 2sin(x)}dx for 0 < x < ∏/6 Or more generally \int\sqrt{a - bsin(x)}dx for a > b How can I solve this? Thanks in advance

1. ∫ 1/(2√(x+3)+x) 2. Not sure if I'm beginging this correctly or not but I get stuck. 3. Let u= √x+3 then u2 = x+3 2udu=dx dx=2√[(x+3) Therefore: ∫1/u2-3 Not sure where to go from here?

Homework Statement Hello all, So I am working on my engineering project, and my professor told us to play with the graphs,and try to find something interesting about them. So what I want to do is form a better fit for the figure below. " figure 2b" , and find out why the choose not to...

Homework Statement A square loop of side 1.5m and Resistance 2Ω is pulled with a constant velocity v=0.3m/s through a smaller region with a constant magnetic field B (out of the page) of 4T. The figure shows the position at t=0. Calculate the magnetic flux of the coil at t=4s.. Here is a...

Homework Statement A square loop of side length L is moving in the x direction with velocity v. v=vx. B points along the z axis and is defined by B=αxez where α is a constant. Find EMF along the loop Hint: Find forces on charges in rod by virtue of motion of the rod.Homework Equations...

How do you prove that: Every perfect square is either a multiple of 3 or one more than a multiple of 3? There is something very basic that I don't seem to understand in the question. Here is proof that someone gave me: Every natural integer p must fall in one of the following case...

basically i have a problem where i am rotating 1 vector to be parallel to another i get the axis of rotation by the cross product of the 2 vectors the angle by the arctangent of the magnitude of the axis and the dot product of the 2 vectors however arctangent2(magnitude(axis) ...

Homework Statement Evaluate the following integral Homework Equations ∫ √(4-(√x)) dx The Attempt at a Solution I am having a mind block, I find this too challenging, help!

I need to know how big of a radius I need to use on an L shaped leg made out of square tubing. Is there a general formula depending on the length and height required? How would I calculate the deflection at the end and the buckling on the vertical part? For the deflection part, would I...

Homework Statement We have a square loop with side length 2a, at xy plane. Now we know ( I have calculated ) that the magnetic field at the center of the square loop to be H = \frac{2I}{\sqrt{2} \pi a} Now we want to know what is the magnetic field at point P, which is on the axis which...

\frac{d}{d \sigma ^2} [log(\sigma ^ 2) - \frac{1}{\sigma ^ 2}] I think the first part is \frac{1}{\sigma ^ 2} but pretty clueless after that. I also want to take the second derivative. Any help or a reference would be great. Thanks!

Hi everyone. Is there any way to set demands on least square solutions? I have an equation on the form Ax=b, which is solved for x as: x=(A'*A)^-1*A'*b I do know for a fact that all values in x should be positive, but the least square solution for my particular system contains a...

This is A and B my friend is telling me that Co is actually 0 and I am getting 1/2 and i don't see exactly what I am doing wrong if i indeed am doing something wrong hopefully someone here can check this out and let me know exactly where i went wrong.. Thanks

I have seen this concept in many places like electrical field, gravitational field, brightness from a distant star or in satellite communication. That is, they seem to be inversely proportional to the square of the distance from the source of that field. What's the reason behind it?

Homework Statement A barn is 100 feet long and 40 feet wide. A cross section of the roof is the inverted catenary y = 31 - 10(ex/20+e-x/20). Find the number of square feet of roofing on the barnHomework Equations Arc Length Integral Hyperbolic trigonometric identities The Attempt at a...

\nabla \cdot \frac{\mathbf{r}}{|r|^3}=4 \pi \delta ^3(\mathbf{r}) What's the proof for this, and what's wrong with the following analysis? The vector field \frac{\mathbf{r}}{|r|^3}=\frac{1}{r^2}\hat{r} can also be written \mathbf{F}=\frac{x}{\sqrt{x^2+y^2+z^2}^3}\hat{x}+...

In your opinion what is the best way to introduce completing the square, in fact I do not like the way sub and add the squared half of x coefficient, after making x^2 coefficient 1 saying it is complicated... Thanks

Hey, it is clear for me that \sum_{i=1}^{n} i = \frac{n(n+1)}{2} how to find a formula for \sum_{i=1}^{n} i^2 \sum_{i=1}^{n} i^3 Thanks

Homework Statement Say that A is a square matrix. Show that the following statements are true, or give a counter example: a) If x is in the nullspace of A, then x is in the nullspace of A2 b) If x is in the nullspace of A2, the x is in the nullspace of A. Homework Equations The...

Hello everyone.. Homework Statement ∫√((1+(e^-x))^2)dx 2. The attempt at a solution I first tried to do a u sub and then attempt a trig sub however I can't do anything with the e^-x left in the u sub. Does anyone have another way I can integrate this thing?? Thank you for any suggestions/help!

Hello, The inverse square law of Newton's gravitational force, is it somehow related to each other? I mean to say P^2 is directly prop.a^3. Is it from the third law that the derivation of inverse sq.law of G=M.m/R2 is derived? Thanks.

[b]1. Consider an ocean current flowing at 2.5m/s a) How much kinetic energy is contained in a cubic volume of water that measures 1m on each side? The density of seawater is about 1030kg/m3 b) If the flow is perpendicular to one of the cube faces, what is the rate at which the current carries...

What are the bond angles in a pentagonal bipyramidal molecule in general? If they vary from molecule to molecule then just the bond angles for IF7 would be ideal. I'd like the same thing for square antiprismatic molecules (any complex ion with coordination number 8 which is square antiprismatic...

θHomework Statement What would be the electric field on the midpoint of each side of a square with point charges of +Q on diagonal corners and -Q on diagonal corners? Homework Equations E=kQ/r^2 Ex=Ecosθ Ey=Esinθ The Attempt at a Solution Considering the midpoint of the side at...

Homework Statement Let G be a finite group in which every element has a square root. That is, for each x in G, there exists a y in G such that y^2=x. Prove every element in G has a unique square root. Homework Equations G being a group means it is a set with operation * satisfying...

The square of the four vector potential. (\phi,A)^2=\phi ^2 - A^2 What's the physical meaning of this lorentz invariant?

Suppose there is an ant at each of the four corners of a square with side length 1, such that (0,0) and (1,1) are at opposite corners of the square. The ant at (0,0) is facing the ant at (1,0) is facing the ant at (1,1) and so forth. Each ant will choose its path such that it is always facing...

Homework Statement The following data is hypothesized to possesses a normal distribution, is that hypothesis sustained by a Chi-square test at .05 significance: <66...4 67-68...24 68-70...35 70-72...15 72-74...8 >74...4 The Attempt at a Solution 1. I know that I should...

Homework Statement Field the electric field of a square sheet. I understand this is a simple problem, I just want to confirm I have the integral set up correctly. Homework Equations \vec{E} = \sigma z \int_{-a/2}^{a/2} \int_{-a/2}^{a/2} \frac{dx' \, dy'}{(x'^2 + y'^2 + z)^{3/2}}...

Homework Statement |x3sqrt(4-x2)dx Homework Equations uv - | vdu The Attempt at a Solution u = x2 v = -1/3(4-x2)3/2 du = -2xdx dv = x(4-x2)1/2 uv - | vdu x2(1/3)(4-x2)3/2 - | 1/3(4-x2)3/2(2xdx) x2(1/3)(4-x2)3/2 +(1/3)|(4-x2)3/2(2xdx) u = 4 - x2 du = -2xdx...

I am reading about the root mean square and Parseval's Theorem but I don't understand how we find $A_0$. So it says the average $\langle x\rangle$ is zero and the $x_{\text{RMS}} = \sqrt{\langle x^2\rangle}$ where $$ \langle x^2\rangle = \frac{1}{\tau}\int_{-\tau/2}^{\tau/2}x^2dt $$ The Fourier...

Homework Statement I have a general question about light and Lumens and the inverse square law? So Intensity = Initial Lumens/Lenth^2 So @ a Length of 1, there is no loss of light intensity. What unit is this 1. 1 meter? 1 foot? Homework Equations The Attempt at a...

Homework Statement Calculate the wavelength of the electromagnetic radiation emitted when an electron makes a transition from the third energy level, E3, to the lowest energy level, E1. Homework Equations E_n = \frac{\left (n_{x}^{2}+n_{y}^{2}+n_{z}^{2} \right) \pi^{2}...

inverse square vs cube = ? If the electric field falls off at the inverse square ratio, and magnetic at inverse cube, does EM radiation dissipate at 1/r^5 ratio for circularly polarized waves?

I am wondering if anyone would be so kind as to help me with a project. I am wondering what size aluminum square tubing it would take to build a "T" with the horizontal top being 4 feet in length and being able to hold 250 lbs. at each end and 1 ft. in from each end, totalling 1,000 lbs. I...

Homework Statement I'm trying to see if I can prove that any non-square number's square root is irrational. I'm using only what I already know how to do ( I like trying to prove things myself before looking up the best proof), so it's going to be round-about. Attempt#1 Eventually required me...

Hi All, I often see this term when factorizing out a matrix from brackets A(some other term)A^T where I assume A A^T represents the square within the bracket term, can someone explain the reasoning behind expressions of this kind or point me in the correct direction Many thanks