Elements Definition and 1000 Threads

Homework Statement The question asks me to determine whether the statement is true or false, the statement being .∅∈{0} Homework Equations The Attempt at a Solution I said that the statement was true, but apparently it is false. Wouldn't a set such as {1,{1}} be made up of the...

Homework Statement Suppose \Omega = \mathbb{R}. Let A_n = [0,\frac{1}{n}]. Let \mathcal{A}=\{A_n:n\in\mathbb{N}\}. Is \{0\} an element of \mathcal{F}=\sigma(\mathcal{A})?Homework Equations The Attempt at a Solution Clearly \lim_{n\rightarrow\infty} A_n = \{0\}. Not sure how to show that it...

Hi all, I would like to know if its possible and consistent to compose the global system matrix with different FEM elements such as frame, plane, shell solid etc... Theoritically all of them will have the same DOF per node just only comprising the local matrix will differ. And as long as we...

In the following circuit, a) identify all combinations of 2 or more circuit elements that are connected in series and b) Identify pairs of circuit elements that are connected in parallel. http://imgur.com/keorO a) Seems easy enough, the 4 and 6 ohm resistors are in series, and so are the 5...

Homework Statement List the elements of the subgroups <3> and <7> in U(20). Homework Equations The Attempt at a Solution U(20)= {1, 3, 7, 9, 11, 13, 17, 19} = <3> = <7>. So basically I have that the common elements of, <3> and <7> and U(20), under + modulo 20, are all...

Hello there! First of all, I couldn't find this topic around here but I could be blind, so if the answer is posted somewhere else, just leave me the link as a response, thank you! :blushing: I am trying to figure out few things about where the heaviest elements come from. I know that Iron...

Homework Statement In the process of trying to prove something else I found it would be helpful if rn\inI, where I is an ideal, n\inN, and r\inR and R is a ring, then r is in I. Homework Equations I is an ideal if a\inI and b\inI then a+b\inI, a\inI and r\inR then ar\inI, and I is not the empty...

Homework Statement If Z2={[0],[1]} with addition and multiplication modulo 2. How many elements does GL(2,Z2)={2 by 2 matrices with determinant 1 and entries from Z2} have? The Attempt at a Solution A\inGL(2,Z2) then det(A)=[1]={...,-3,-1,1,3,5,...} Suppose A=|a b:c d| then...

Homework Statement Ok so this satellite is orbiting the earth. The position vector is r = -0.707i + 0.707j + 0k and velocity vector is v = 0i + 0.5j + 0k. To find Vo (the angle between vector n and e), my book said the formula to use is arccos{(e dot r)/(|e||r|)}. However, I got 98 degree by...

I thought all heavy elements came from supernovae, but a recent article by John Baez corrected my ignorance. There is a nice photo too at http://math.ucr.edu/home/baez/diary/index.html#now

Hi i need a little help i was given group (Z3 x Z3,+) and i should find order of every elements so the elements are {(0,0),(0,1),(0,2),(1,0),(1,1),(1,2),(2,0),(2,1),( 2,2)} and the order of every element is (0,0) has order 1 (0,1)*3=(0(mod 3),3(mod 3)) = (0,0) order 3 (0,2)*3=(0(mod...

By choosing among the following five options, what is the main source in the universe for the origin of the elements : silicon, lithium, bismuth, nickel and uranium? Primordial nucleosynthesis – fusion in core of low-mass stars – fusion in core of high-mass stars – slow neutron capture in...

By choosing among the following five options, what is the main source in the universe for the origin of the elements : silicon, lithium, bismuth, nickel and uranium? Primordial nucleosynthesis – fusion in core of low-mass stars – fusion in core of high-mass stars – slow neutron capture in...

I have an array of 3 known elements.I know that 2 elements of them have the sum of 100 and I need to find the location of the two elements which have this sum ex. A[3] 5 25 75 the solution for this prob. is second & third location Thanks,

I'm looking for a Real Analysis book to start with, besides Spivak. On Amazon, one of the reviewers said it was good as a subsequent book for learning Functional Analysis/Lebesque Integration, while another said it was a good introduction to Real Analysis. For those of you that have read it...

Homework Statement Prove that for a finite group A, the order of any element in A divides the order of A. Homework Equations The order of an element a of a group A is the smallest positive interger n such that an = 1. The Attempt at a Solution Well, I know that the order of a...

Sample space of rolling a 6 sided die I've just had my first tutorial for an introductory probability class taught by the Econometrics department and I'm having trouble understanding why my solution is wrong. The tutor didn't write up complete solutions(just pictures to help visualise the...

Alright so, I decided to read some Euclid's Elements for my own personal gain (became interested while reading Stewart's Precal, and I think it might help with Calculus) and I'm stuck on proposition 7, mainly because I really want to understand the reasoning behind it and I just can't seem to...

Hi. The proof that I'm working is in the title. The Defition of "same number as" is given as follows: (1) Two sets S and T are said to have the same nuber of elements if each element of S can be paired with precisely one element of T in such a way that every element of T is paired with precisely...

I have one main program where I have calculated some array, say A(i,j) If I want ot use the values in subroutine, and calculate some more values and give back the result to main program, how my syntax should be? I tried this way. Its not working. program a...

Can there be repeated elements within a group?

Proposition: If every element of G/H has finite order, and every element of H has finite order, then every element of G has finite order. Proof: Let G be a group with normal subgroup H. Suppose that every element of G/H has finite order and that every element of H has finite order. We wish to...

Hi, I haven't taken any set theory course during my studies and this is a query of mine, though to many of you that are familiar with this subject might seem naive. Any suggestions would be useful. Many thanks

Is it necessary to know the proofs of all the propositions in Euclid's elements? Or one can directly jump to euclidean and precollege geometry, of course he/she will have knowledge of propositions( just the statements and all that) but not the proofs. Reply Quickly.

Homework Statement How many elements are in the set below? {1,2,{3},{4,5},6,{{7}8}} Homework Equations The Attempt at a Solution I heared that the best way is to take of the {} each time. But can somebody tell me the real rules for how to find solutions for this question...

Prove ord(a) = ord (bab-1). Attempt at the proof. Proof: Let G be a group and let a,b ε G. (=>) Suppose ord(a)=n. That is, an=e. We wish to that the ord(bab-1)=n. If we take an=e and multiply on the left by b and on the right by b-1 then, we have, (1) an=e...

Can't you take a proton out of a mercury atom for example so the atomic number can change from 80 to 79 so it can become a gold atom?

I have no prior knowledge on engineering, but has just started my Msc dissertation about using nonlinear programming technique to model a problem that is related to spacecraft elements design. I am uncertain that whether I have fully understood the problem. The problem is to decide the...

Homework Statement I have a matrix that contains zeros but it may contain also ones. For example: ID=[1 0 0 0; 0 0 0 0; 1 0 1 1] I'm trying to replace all the ones by zeros and all the zeros by elements of an array EA going...

Hello again! Let's say that i am calculating every element of a 100X300 table by using equation A I use two for loops (i m doing this in matlab) for i=1:100 for j=1:300 element(i,j)=... (it is the equation A) end end equation A involves the neighboring elements What...

Homework Statement Let V be a vector space and v, w two elements of V. If v+w=O, show that w=-v Homework Equations The Attempt at a Solution This is my attempt: 1. v+w=O 2. v+(-v)=O 3. v+w=v+(-v). Subtracting v from both sides yields: 4. w=-v The solution...

The greatest lower bound and least upper bound of two elements a, b in a lattice do not have to be unique, do they? It could be the case that two equivalent or non-comparable glb or lub exist, right?

is it possible to make a venn diagram wherein the elements are infinite elements? ex. V = { is the set of all odd numbers) W = { 5, 15, 25, 45, 55,...} thanks a lot

Why aren't mixed ratios allowed in Euclid's "Elements"? Why did Euclid forbid the comparing of different kinds of magnitudes? And was it the same for numbers? Or were ratios specifically meant for magnitudes (lines, planes, solids) What are the consequences of comparing 2 different kinds of...

did the heavier elements come from different galaxys? I am a gcse student who is in a bit of a debate with my teacher :)

So Arsenic is poisonous to Oxygen based life forms (Humans). What would be poisonous to a Sulfur based life form (if they exsisted)?

I have to describle the elements of the quotient ring $$\frac{\mathbb{Z}[x]}{2\mathbb{Z}[x]+x^2\mathbb{Z}[x]}$$ do I use the division algorithm to write any element as $$f(x)=(x^2+2)q(x)+r(x)$$ where $\operatorname{deg}(r(x))<2$ so the elements of the ring are the linear polynomials over...

Homework Statement Let assume that we have two rectangular prism elements of similar dimensions: e.g. 1.) x0=100.1, y0=100.2, z0=90.4 2.) x0=100.2, y0=100.4, z0=90.0 How can I calculate the stress tensor of each of the two elements if I assembly them by merging their z-y faces...

When chracterizing the definition of unique factorization domain ring, the Hungerford's text, for example, states that UFD1 any nonzero nonunit element x is written as x=c_1. . .c_n. Does this mean any nonzero nonunit element is always written as a product of finitely many irreducible...

Algorithm for finding best (or combinations of) "non-overlapping" matrix elements. I'm looking for the best general way to find the "best" combination for a list of non-overlapping matrix elements. For example, given the matrix AE BE CE DE AF BF CF DF AG BG CG DG AH BH CH DH...

I am baffled at the answers to the following HW quesitons compared with what I thought I knew about the topic. Hoping I can get my misunderstandings cleared up. Question 1 How many lines are expected on a detector plate of a Stern-Gerlach experiment if a beam of a) potassium atoms b)...

Hello again everyone, Physics Noob is back again. I had a question about solar formation that has me stumped. If you hadn't read my previous post, I am a newcomer and hobbist of physics so don't expect me to know everything or equations on physics. Again, I may come off sounding like an...

Hi, Homework Statement Show that for every x in (Z/ 7161 Z)*, the order of x divides 30. Homework Equations (Z/ 7161 Z)* is the group of units of Z/ 7161 Z. The Attempt at a Solution I factorised 7161: 7161 = 3 * 7 * 11 * 31 I used the Chinese remainder theorem to show that (Z/...

Hi, I somewhat know the basics about black holes. Tell me if I'm wrong. --A black hole is formed when a supermassive star (one of many theories of the formation of black holes) burns out due to exhausted fusion reactions. It can no longer support its own mass and the core collapses in on...

"The Set of all elements X" ? What does this mean? I know it's really simple but I don't understand what it means. In set builder notation when I'm describing a particular set I know for example: {10,11,12,13,14,15} is {x |x is a whole number greater than 9 less than 16} and is read "the set...

let A={z|z^6=√3 + i} B=(z|Im(z)>0} and C={z|Re(z)>0} find A∩B∩C the part previous to this qn asks me to find the roots of z^6 and I've already down that. but i have no idea how to proceed with this, so do i draw my unit ciorcle with the hexagon and then follow to see what regions satisfies with...

we are currently learning about radioactivity and i have become curious of how these heavier elements came to Earth in the first place? From what i understand, the lighter elements are formed by fusion in stars, but even so, how could these lighter elements reach us when the stars are so far...

Hello. I have a question about ionization energy: Two hypothetical elements in the 2nd or 3rd period have the following ionization energies: Element X First: 800 kJ/mol Second: 2500 kJ/mol Third: 3900 kJ/mol Fourth: 23000 kJ/mol Element Y First: 700 kJ/mol Second: 2200 kJ/mol...

Hello, I have been very obsessed with a board game called Hex lately. I am trying to calculate the number of completed states (all positions filled in) on a 3x3 board where a certain player wins, given that some positions are already filled. I have attached a diagram illustrating what I am...

If super nova is responsible for all elements on earth, including the ones that humans were made from, why aren't all elements found on every planet?