Writing Definition and 688 Threads

I need to write, (k)1/2= a finite term polynomial of 'k' where 'k' is the set of all Reals where 'k' is greater than 0 in math. Thanks!

Hello, Im trying to simulate a VCVS by writing this netlist on PSpice: ***Voltage controlled voltage sources(VCVS)*** *#destroy all *#run *#print all .TF V(Vout,0) Vin Vin Vin 0 DC 1 R1 Vb 0 3K R2 Vt Vout 1K R3 Vout 0 2k E1 Vt Vb Vin 0 23 .end But it keeps giving me...

I'm currently writing a book about a nuclear epidemic and it came to my attention that I know nothing about nuclear... Let's say radiation existed as a mere 2% of the atmosphere in a certain location, would it be possible to say all those 'infected' with the radiation in the atmosphere would...

conflict? I'm currently starting to write a dissertation for my 3rd year project and wondering if someone could give me some advice? I'm finding published research papers that conflict each other, obviously up until now I have taken them and anything in textbooks as gospel. But now I'm in the...

Is it possible to convert a general linear second order boundary value ode y'' + P(x)y' + Q(x)y = g(x), y(a) = y_a, y(b) = y_b to a Fredholm integral equation, explicitly determining the Kernel in the process, without removing the y' term? (Here is an example of doing it without the y'...

Hi :) What are the basic steps of writing an article, doing a research on math? The one study a specific topic or topics, then you make some claims and try to prove them? Thanks :)

Homework Statement Potassium chromate is an important compound of chromium. It is composed of K+ and CrO42-. Write the formula of the compound. Homework Equations positive charge + negative charge = 0 The Attempt at a Solution I know how to do this problem by cross switching the...

Hello :) That's my 2nd year in Math, and I want to start writing an article on NT or Group Theory. I know most of the basic GT and some NT. I still don't know residues/congruences completely, I face problems about understanding the theorems. There are a lot of theorems in these chapters and...

Homework Statement this is the original question prove: \forall c \in Z, a≠ 0 and b both \in Z$ a|b ⇔ c*a|c*b Then he corrected himself by saying for problem 1: to show that ca | cb implies a | b ... you must assume c NOT = 0 and invoke "Cancellation Property" of Z. This kind...

Is "0<d,l<1" equivalent to writing separately "0<d<1" and "0<l<1"? Dear all, I'm writing a paper for a scientific journal and I need to save as much typographic space as I can. In a proposition, I need to specify that the parameters "d" and "l" assume values between zero and one. I am wondering...

Homework Statement Given a system like: \\a x^2 + b xy + c y^2 + d x + e y + f = 0 \\g x^2 + h xy + i y^2 + j x + k y + l = 0 How write it in matrix form? Homework Equations The Attempt at a Solution \begin{matrix} a x^2 + b xy + c y^2\\ g x^2 + h xy + i y^2\\ \end{matrix} +...

Hello everyone, I take notes strictly with Latex, as I am able to get more done in a day by not taking hand written notes; and lately I have been contemplating using latex to write up solutions to problems for the same reason, that I might get more done in a day. My concern is, however, that...

So I've done a little research on EMP and I know how they disable electronics, but I don't quite understand the aftermath. If planet 'A' gets hit with a MASSIVE pulse, or several less massive pulses, would flora and fauna be directly affected? All the electronics present on 'A' would...

Good morning everyone. I would love some insight regarding mechanical engineering and writing code. My physics professor (who also has a masters in electrical engineering) mentioned last night that the ability to write code (I apologize if I am using the term incorrectly...still kinda new to...

The result of multiplying 2 by x plus y times 3 plus 5 times z is equal to 10. 2x + y * 3 + 5 * z = 10 2x + 3y + 5z = 10 or 2 (x + y * 3 + 5 * z) = 10 2x + 2y + 6 + 10 + 2z = 10 2x + 2y + 16 + 2z = 10 Can someone please check this for me and tell me which way is right? I forgot how to do...

Homework Statement Let ##\phi## be defined as follows: ##\phi(t)=\frac{sint}{t}## if ##t \neq 0## ##\phi(t)=1## if ##t = 0## prove it's derivable on ##\mathbb{R}## now let f be: ##f(x,y)=\frac{cosx-cosy}{x-y}## if ##x \neq y## ##f(x,y)=-sinx ## in any other case express f as a...

Homework Statement I'm having trouble writing a sum for this: https://scontent-b-mia.xx.fbcdn.net/hphotos-frc3/v/1420232_10201136345792485_382911431_n.jpg?oh=ebd9432103184956c863370121e326ce&oe=529332ED Homework Equations delta x = (b-a)/n n = 4 b-a = 2 delta x = 1/2 The...

Hello MHB, I am in the process of writing my thesis. I need some guidance on the same. I need results from basic real analysis. I will be happy to provide their proofs in my thesis but I am not sure whether or not it is appropriate. In other words, I am not sure what do people expect to see...

Compose the equation for the reaction of fluoride with potassium nitrate. State the spectator ions. Here is my attempt: K(NO3)2 + F- = N2O6 + KF Or is it K(NO3)2 + NaF = Na(NO3)2 + FK I think the spectator ions are K- and NO3 Any ideas? Thanks

Prove that every n E N can be written as a product of odd integer and a non-negative integer power of 2. For instance: 36 = 22 * 9

Hi, I have a question that I don't know where to start on! First, some necessary background info: $r$ denotes reflection about the $x$-axis. $t_a$ denotes translation by a vector $a$ $p_{\theta}$ denotes rotation by an angle $\theta$ about the origin Let $s$ be the rotation of the...

Firstly, it's darn hard work, and any notion I had about overtaking Crawford's, Lights Out, have been dealt a painful blow. He became a multimillionaire in the time it takes the photons leaving your monitor to pass the end of your nose. Well, so it's said. I talked at length to Richard...

Homework Statement So as a part of a very long question on homework for thermodynamics, I and some of my friends got into a debate about how to write an expression for entropy at a particular state. Homework Equations delS(state 1 to 2)= Cv*ln(T2/T1)+R*ln(V2/V1) (from constitutive...

so solving lim's can be tedious not because they are hard but because you have to continously keep writing lim x->a while solving the equation is there a mathematical shortcut to writing limits without keep writing lim x->a all the time after each development? thanks.

Hi, Wasn't sure if I should post this to Linear Algebra or here. My question is really simple: Can a 2N by 2N random, and Hermitian Matrix ( Hamiltonian ) be always written as: H = A \otimes I_{2\times 2} + B \otimes \sigma_x + C \otimes \sigma_y + D \otimes \sigma_z where A,B,C,D are all...

I haven't seen it asked on this forum before, so here goes: I am coming up on a third official attempt on the general (computer based) GRE soon. In my first two attempts I have not been able to break 50th percentile on the quant section, which is embarrassing. I have discovered that I do much...

Homework Statement Through donations the food bank tries to feed as many people as possible. Assume there are no backorders - any unsatisfied demand is lost. The food bank also has limited facilities to store donations, 200,000lbs maximum can be held in storage. Assume donations are processed...

I just started this topic and have a question: For a positive continuous random variable X, write down the PDF of Y = X^2 in terms of the PDF of X. So; writing the PDF of X, I get P(0<X<∞) =integral from 0 to ∞ fx(x)dx Is this correct? For Y=X^2, wouldn't the pdf be the exact same thing...

Hi folks! I've considered a career as a technical writer for the mechatronics/electronics fields for a while now (yes I have engineering education), but I'm wondering if I'd want to work in a European country like Netherlands, Germany...do they need technical writers in English? Or, do they...

Hi All, I have an equation like this: \sum_{i=0}^{n} x^{i}*y^{i} is there a way to re-express this equation by writing x and y separate? Thank you

I'm not exactly in college yet but will be soon. Looking at several threads, reus are extremely competitive, especially for freshmen. Many say to apply to ten or fifteen of them. But is it typical to send that many LoRs for one student?

Is there is a problem in writing an expository article in a college science magazine run by a student group on a topic similar to research that I did over the summer? I thought it was very interesting and included some material from articles which I looked at then. The main reason why I'm...

Homework Statement write an equation for the reaction and state the systematic name of the ester formed 3-methyl-1-butanol was mixed with ethanoic acid and refluxed for approx. 40 mins the mixture was washed in a separating funnel with distilled water, then sodium carbonate, then...

What can it be about? How do we ascertain the novelty of the intended paper? How should it be structured? Where should it be submitted and how? What can it be written in and what format should it be forwarded in? Any advice is appreciated. Thank you.

Having taken many years to write a huge tome, I'm surprised and very pleased to find this section of the forum. I have already asked about the math involved in accelerating a huge vessel in space, but was acutely aware of typical forum rules about self-promotion. I really would like some...

I'm studying for our comprehensive exam . I just need to clarify something. So the equation of motion for lagrangian dynamics is \frac{d}{dt}\frac{\partial L}{\partial\dot{q}_{i}} = \frac{\partial L}{\partial {q}_{i}} However, in my notes there are example which uses the principle of virtual...

Hello all, I have been tasked with actually writing my own paper for the ApJ, rather than just submitting my results to my professor and letting him do the work. So, my question is this: Is there a place where I can get a sample tex file from the ApJ? I've seen many crap example files...

Homework Statement EXPONENTIAL FUNCTION The graph represents a transformation of the function f(x) = 2^x, Write an equation for it. The graph in question is the second one, graph B. http://ars.els-cdn.com/content/image/1-s2.0-S0006349598778683-gr1.gif Since there are more variables...

In a rigorous mathematical course I am talking, it seems to make a difference when I am given a function f and need to write its Fourier series, whether it is defined on [0,2∏] or [0,2∏). What difference does it make for my series whether it is an open or a closed interval?

Problem: Prove that any element in the intersection of two sets is also in their union. I am reading a proof writing book for dummies & the solution given in text is: http://tinypic.com/r/141hn7/5 http://tinypic.com/r/141hn7/5 First Question: In exam/test, is it OK if I write the...

Homework Statement Four 3-vectors a, b, c, and d are related by the equation ax + by + cz = d; where x, y, and z are real parameters. Using a suitable combination of scalar and vector products, findd x, y, and z in terms of the vectors Homework Equations The Attempt at a...

Homework Statement What is the pH of a buffer solution created by combining 100 mL of 0.2 M acetic acid and 400 mL of 0.10 M sodium acetate? Ka= 1.8 x 10^(-5)Homework Equations 1.8 x 10-5=([C2H3O2-][H+])/([HC2H3O2]) The Attempt at a Solution I know what I'm supposed to do to solve this...

I need help with some set notation. I am an engineering major and don't know the proper notation. I am trying to write two statements. I have two sets, x_1 = {1,2,3}, and x_2 = {4,5,6}. Verbal Statements: y_1 was measured for all values of x_1 and x_2 y_2 was measured, for all values of...

Homework Statement A baseball strikes a bat. It's moving at 40m/s to the left horizontally. When it hits the bat it leaves at 60m/s with an angle of 30 degrees to the horizontal. The mass of the ball is 0.25kg. Homework Equations P(momentum)=mv Pf-Pi=ΔP ΔP=J(impulse) The Attempt at a Solution...

Hello! One of the many aspects of math that I'm intrigued by is pedagogy. I find that many times folks grow up thinking certain mathematical statements that in the end may be inaccurate, or totally false. I came across a little pic on the internet, and it says "f(x) is just a fancy way of...

Is anybody here able to work as well on the computer with something such as latex as with pencil and paper? Sometimes I think it would be nice to just carry my computer with me, and not fifty pages of blank paper, pencils, erasers, etc. I'd like to be able to sit and work anywhere, not...

Writing essays using Lyx: Where is the mac version gone?? Dear PFers, Im a young-old-time-Latex user and I always use Lyx when doing simple reports like Laboratory reports (as a good and stable GUI). Ever once in a while, I format all my electronic devices (and i mean all of them, even the...

Homework Statement Let f : A → B be a function and let S, T \subseteq A and U, V \subseteq B: Prove that if U \subseteq V; then f-1(U) \subseteq f-1(V): Homework Equations Preimage: f-1(U) = {x \in f-1(U) \ni f(x) \subseteq U} The Attempt at a Solution Assume U \subseteq...

Homework Statement Let f: A --> B be a function and let S, T \subseteq A and U, V \subseteq B. Give a counterexample to the statement: If f (S) \subseteq f (T); then S \subseteq T: Homework Equations The Attempt at a Solution PF: Assume f(S) \subseteq f(T). Let x \in...

I am new at the forums and still getting used to writing in Latex. I found that it is easier for me to write my LateX in this editor: http://www.codecogs.com/latex/eqneditor.php and then copy to the physics forum. So, I wanted to ask you guys, do you know any other tricks you want to...