Elements Definition and 984 Threads

Homework Statement Suppose that G is a group in which every non-identity element has order two. show that G is commutative. Homework Equations The Attempt at a Solution DOES THIS ANSWER THE QUESTION?: Notice first that x2 = 1 is equivalent to x = x−1. Since every element of G...

Hello, Let's say I have 500 boxes and 500 hundred non-identical items. I would like to have sets of 40, chosen among those 500 hundred items and my objective is to keep the number of same items in any 2 boxes at a minimum. 1. What would be that minimum number of common items? 2. If...

Give one primitive element for each of the finite field: F2n (here "2" is the subscript) for n=1, n=2,...,n=8

Homework Statement This problem is insanely intuitive. Define f : (0,1) \rightarrow \Re by f(x)=\begin{cases} 1/q&\text{if } x \neq 0 \text{, is rational, and }x = p/q \text{in lowest terms}\\ 0&\text{otherwise }\end{cases} Suppose \epsilon > 0. Prove that there are at most a...

I 'cheated' and used GAP to compute these, but I want to make sure I am thinking through these properly. This isn't homework as much as given answers in an example and I'm not sure how they computed them. S_12 (1,2)(3,4)(5,6)(7,8)(9,10)(11,12) - 10,395 This stems from...

Three resistors and a capacitor are in a circuit with a battery: R1 = 23 Ω R2 = 13 Ω R3 = 15 Ω C = 6.2 µF V = 17 V The switch has been closed for a long time. What will the charge be on the capacitor 195 μs after the switch is opened? picture...

ANSYS Help: Simple Modal Analysis of Plate I am modeling a plate (36"x3"x.25") in ANSYS. When I construct a line out of two keypoints and give the line a rectangular section, the analysis works and I can output modal displacements just fine. With these modal displacements I can plot the mode...

Given a set of sets such that A_{i}\subset{C}. Every subset has a countable infinity of elements. I want to create a set W such that it contains exactly one element from each subset A_{i}. I presume I can do this by describing the intersect of W with every subset A_{i} as containing exactly one...

Homework Statement you are given a vector y construct a MATLAB script program to shift all element of y left by ( n ) position.. I mean if y=[1 5 6 9 3] and n=2 by apply this program on y we have : y=[3 1 5 6 9] The Attempt at a Solution this is my Attempt to solve this...

Statement: I was wondering if someone could provide more background knowledge on why certain elements in a circuit (e.g. capacitors) are associated with imaginary components, whereas other elements (e.g. resistors) are only associated with the real components. In particular, the equation below...

how is it known that iron is formed in stars and not anything heavier? And how is it known that elements like uranium arent in fact formed in the cores of stars prior to supernova? answers much appreciated

This is something which has been a question to me that I don't seem to have stumbled across anything about myself: How and when did/do the elements above Iron get created? I've come across mention about the elements up to iron being generated by the process of fusion in stars. I assume...

C programme ? Homework Statement /* Program-8.4 */ #include <stdio.h> int main() { int marks[5]= {89, 45, 73, 98, 39}; printf("%d\n", marks); //memory addres pointed by pointer printf("%d\n", &marks[0]); //memory address of 1st element printf("%d\n", *marks)...

Hello everyone, During the last few days I've been working to solve a "small" problem I hope someone here might be better at than I am. I'm writing a function that returns the state vectors of an orbiting body of neglible mass based on the orbital elements semimajor axis, semiminor axis...

From the primal plasma how many elements (could) have formed that are not detected? or is the larder full.

Hello all, I was wondering if there was a way to calculate the reflectivity of differing wavelengths of light hitting an element based upon its physical properties. I know that it is based on how the atoms of the material are excited based upon the wavelength hitting it. I eventually want to...

Homework Statement which elements of z42 are invertibles? Homework Equations The Attempt at a Solution In my notes I have that invertibles are relatively prime to the order of the group. So I have 1, 5, 11, 13, 17, 19, 23, 25, 29, 31, 37, 41. Is that the case for all groups?

Homework Statement Predict the sign of ΔS(sys) for each of the following processes: a) Zn(s)+2HCl(aq)-->H2(g)+ZnCl2(aq) b) CH3CH2CH3(g)+5O2(g)-->3CO2(g)+4H2O(l) Also, I'm not sure but when we're evaluating questions like these, do we count the number of moles only of solids, aqueous and...

Show that the Cardinality of a set which doesn't include inverse elements from a group G is always even. So the set with all g in G, which includes no inverse elements from G. (g=!g^-1) I can get this in every example I've done, checking mainly with dihedral groups, it's always been true but I...

Without Sylow's theorems! This was a problem at the end of a chapter on Lagrange's theorem. I know that every subgroup of order 77 is cyclic. But I don't know how to prove this using only Lagrange. Any suggestions?

Okay, so, in science class today, we learned about atoms and compounds and whatnot And I said to my teacher that I read somewhere that there are 131 elements, and she said that there are 90 main ones and about 17 others, and so she said that if I researched this some more, tell her. The book...

Hello everyone. May I ask if it's possible dark matter consists of trans-Seaborg elements beyond atomic number 126? Seaborg hypothesized that these elements were an "island of stability" and may be stable. Would we know enough of the chemical properties of such new elements to say that this...

Hey guys, I'm having a massive brain freeze here trying to show that for any element g in the unitary group you can always represent it as s*some diagonal matrix*s^-1. The only requirement for an element to be unitary is that its hermitian conjugate is its inverse correct? Any hints/help would...

I need to convert a 2D code to 1D for a simply supported beam using matlab. Does anyone have any experience regarding to this?

I'm studying the proof that the l2 metric space is complete and I just don't get something about this proof. What I know: l2 is the metric space whose elements are sequences that converge when you square each term and sum them. In other words, a sequence, f is in l2 if SUM( |f(k)|2) <...

Has anyone taught geometry at the high school level using Euclid's Elements (e.g., http://www.perseus.tufts.edu/cgi-bin/ptext?lookup=Euc.+toc") as a textbook? Einstein considered the Elements a "holy little geometry book."

I am trying to find a clear answer as to why elements' weights vary, when their makeup are of the same protons, electrons, and neutrons? For example, H = 1.0079 atomic weight, 1 proton + 1 electron Li = 6.941 atomic weight, 3 protons + 3 electrons + 4 neutrons If a neutron = 1 proton + 1...

Let X = \{1,2,\cdots, p\} with p prime, and Y = \{1,2,\cdots,t,i_1,i_2,\cdots,i_{p - t}\} with 1\leq t\leq p - 1 and i_j\not\in X for 1\leq j\leq p - t. Supose that a and b are both p-rotation in X and Y, respectively. Whether or not p don't divide the order of ab?

I just went down to see my three-week old grand-niece. I have three grand-nephews on my side of the family and at least two on my wife's, she's not sure. This newly discovered particle has the following TOE: There are 4 elements, mommy, daddy, food, and sleep. Then there is the quintessential...

*This isn't actually coursework but i was under the assumption that questions go to this forum* Homework Statement Hi, for while I've been under the impression that spectral lines of all the elements can be calculated. I did some research and found that there is a simple equation (Rydberg...

Homework Statement Find the inverse for each element in the group {1, 9, 16, 22, 29, 53, 74, 79, 81}, which is under modulo91 Homework Equations The Attempt at a Solution From notes (again): 1 = 1 9 = 81 16 = 74 22 = 29 53 = 79 How were these numbers found? Sorry for so...

How do I go about showing A_4 \not\cong S_4 So far the only argument I've been able to come up with is that the order of the elements of the two groups differ. Is this sufficient to conclude the two groups aren't isomorphic - it just doesn't seem that rigorous to me.

Whats the best method for this? Just removing electrons, how long will the ionized state last, and can I do it in a makeshift kind of way with household/cheap parts?

hi all, here's an interesting problem I've been working on in MATLAB. any help would be appreciated. i have four column vectors of length ~11000 (table1): in1 in2 out1 out2 11 4 101 47 1 8 111 9 38 1 1 39 ... i also have a matrix with dimensions 111x111 (matrix1): c1 c2...

I'm thinking about getting this book. I'm a physics major, and I think the only analysis course I'm required to take later as a prerequisite for graduate courses is Introduction to Complex Analysis. So far, I've taken Cal I-III and Linear Algebra. Differential Equations will probably be in the...

Hello I have a question if anyone know the answer I appreiatete it, the question is that when doing FEM for a frame in just 4 elements is more correct to solve it by using stiffness matrix and spread sheets or by using ProE is more correct answer can be found, please can you explain it for me...

Folks, this is my first thread in this forum. I'm writing my PhD about HTR-Fuel Elements. I'm not quite sure if anyone in this forum knows about this sort of fuel which is totally different to "normal" fuel. Anyway, I'm looking for informations about research in the US (or global) what...

the asymptotic lower bound for sorting n elements is n*log(n). what about sorting a set of n elements when you know that they only take on k distinct values? does n*log(k) sound right?

"Let f is a polynomial from k[x,y], where k is a field. Suppose that x appears in f with positive degree. We view f as an element of k(y)[x], that is polynomial in x whose coefficients are rational functions of y." I think I am missing something...why do we need rational functions here? can't...

http://img525.imageshack.us/img525/2290/84419342em1.th.gif in case A: S has a bigger electonegative energy then Ca so it will "take" 2 electrons from Ca inorder to be a complete gas like (Ar) so i know why there is +2 on Ca and -2 on S . Ca has after perfect gas 4S^2 S...

This is from Hartle's GR book, in one of the first chapters it talks about diff geom, nothing too advanced, but I am learning on my own. Homework Statement It's part E I have trouble with. Read e. and skip to last para if you want. Consider this coordinate transformation: x=uv ...

I have been having a very difficult time grasping the concept of voltage drops across resistive elements. In a series configuration...How is it that the greater the value of the resistor, the greater the voltage drop across that resistor? Why does voltage distribute itself that way, in...

FEM -- mesh generator, transition elements Hello, I would like to implement 2D mesh generator. Mesh should consists of triangle and rectangle elements and those triangle elements will play a role of transition elements. The example of such mesh is here: http://pkow.pl/transition_element.jpg...

Hi! In my work I use the WE theorem to evaluate matrix elements. F being the total spin and m the projection onto the z-axis, I am using: <JIFm|r_(-q)|J'IF'm'>=(-1)^(F'+m'-m)<Fm1q|F'm'>sqrt(2F+1)sixj(F, F', 1:J',J,I)<J'||r||J> I have a problem with the (-1)^ part which I suspect to be...

for those of you who've done it, how long does it take to read it? all 13 books.

Homework Statement A circuit contains only two of the three elements L,C ,R. When connected to a 120 V , 60 HZ ac generator, the current of 6.4 A lags the voltage by 30o. What are the two elements and their values? Homework Equations The Attempt at a...

state whether the following statements are ture or false. give reason for that, 1. any finite group has an even number of elements. 2. there exists a field containing exactly 4 elements. 3. the dimension of a finite dimensional vector space is dividible by the dimension of any subspace.

Homework Statement Compute the direct sum Z_12 (+) U(10) Z_24 is the group Z under addition modulo 12 U(10) is the group Z under multiplication modulo 10 The Attempt at a Solution I have computed direct sums of Z_n groups before: For example: Z_2 (+) Z_3 =...

I want to make a heated steering wheel for my car using hand warmers from a snowmobile. The power source is 12 VDC and the resistance is 10.0 ohms using 25 watts on the low setting and 19.6 ohms using 35 watts on high. That is for one handwarmer, I figure I will need about 20 of them. Will...

[b] Show that any group of even order has at least an element of order 2 Homework Equations [b]3. I know that the order of a groups tells you how many elements the group consist, but just randomly assuming that it has at least an order of 2 is what I can't really understand. For example...