Writing Definition and 712 Threads

  1. mesa

    Writing a Finite Polynomial for (k)1/2 in Math | Real Numbers

    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!
  2. D

    Simulate a VCVS by writing this netlist on PSpice

    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...
  3. M

    I need the help of a scientist with writing my book about nuclear

    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...
  4. R

    What do you do when writing a dissertation and research papers conflic

    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...
  5. B

    Writing y′′+P(x)y′+Q(x)y=g(x) as a Fredholm Integral Equation

    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'...
  6. D

    How Do You Write a Research Paper in Mathematics?

    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 :)
  7. BrainMan

    Writing Ionic Formulas, Given the ions

    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...
  8. A

    Cancellation Fontys Engineering Physics. Need Help On Writing An Email

    Hello guys, I applied for Engineering Physics, and I got admitted..and after a month, they sent me an email telling me that the program was canceled, and told me to inform them about my second choice which is ICT . so please guys I need you to give me some ideas on how to start the email...
  9. G

    How to start writing a paper on Number Theory or Group Theory

    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...
  10. M

    Divisibility Proof Writing: Exploring the Cancellation Property in Z

    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...
  11. F

    Is 0<d,l<1 equivalent to writing separately 0<d<1 and 0<l<1 ?

    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...
  12. J

    Writing a system of conic equations

    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} +...
  13. B

    LaTeX Latex vs Hand Writing: Can Computer Notes Aid in Memory Recall?

    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...
  14. B

    Writing a book and I need some facts if you'd be so kind.

    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...
  15. D

    Mechanical Engineering & Writing Code: Benefits & Recommended Languages

    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...
  16. J

    MHB Writing equation from a description

    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...
  17. F

    Writing a function as a function of another function

    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...
  18. Q

    Solving Sum HW Trouble: b-a=2, n=4, delta x=1/2

    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...
  19. caffeinemachine

    MHB Guidelines on Writing a Math Thesis

    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...
  20. S

    What Happens When Fluoride Reacts with Potassium Nitrate?

    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
  21. K

    MHB Can Every Integer Be Decomposed into an Odd Integer and a Power of 2?

    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
  22. K

    MHB Writing formulas to describe isometries

    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...
  23. R

    Is Writing a Sci-Fi Novel as Challenging as Becoming a Bestseller?

    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...
  24. U

    Can Absolute Entropy Be Calculated Directly from State Variables?

    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...
  25. Z

    Is There a Shortcut for Writing Limits in Math?

    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.
  26. S

    Writing a random 2N by 2N matrix in terms of Pauli Matrices

    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...
  27. L

    Skipping the Analytical Writing part on the GRE.

    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...
  28. U

    Writing expressions, Markov Models

    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...
  29. T

    Writing Matlab program for Newton Raphson

    Homework Statement Two forces P and Q are applied at the end of a screw eye in order to remove the post. 1.)variations (plots) of P and Q versus (theta) for a given value. R=800 N 2.) for what value of theta we obtain P=Q? Homework Equations...
  30. N

    MHB PDF of X^2: General Method & Question Answered

    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...
  31. Femme_physics

    Engineering Technical Writing (in engineering fields) and English

    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...
  32. F

    Way to re-express this equation by writing x and y separate?

    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
  33. K

    Do professors hate writing multiple LoRs?

    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?
  34. M

    Writing an article for a student publication

    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...
  35. 5

    Writing an equation for a ester formed through reflux

    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...
  36. Pejeu

    Advice and general guidance on writing and submission of a math paper?

    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.
  37. R

    Request for comments about over-complication when writing sci-fi

    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...
  38. J

    When do I need to use virtual work in writing the equations of motion?

    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...
  39. Adoniram

    Writing an article for The Astrophysical Journal

    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...
  40. N

    Writing the equation of a transformed exp function given the graph

    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...
  41. A

    Writing Fourier Series for Open and Closed Intervals

    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?
  42. W

    Proof Writing for Dummies: Intersection & Union Elements

    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...
  43. J

    Writing parameters in terms of given vectors

    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...
  44. J

    Writing Common Ion Concentration in Buffer Eq. Expression

    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...
  45. B

    Need help with writing set notation.

    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...
  46. X

    Writing impulse in vector notation

    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...
  47. Bruce Wayne1

    MHB Statement "f(x) is just a fancy way of writing y" factually incorrect?

    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...
  48. dkotschessaa

    LaTeX Latex vs Writing Math: Can I Achieve Fluency?

    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...
  49. A

    Writing essays using Lyx: Where is the mac version gone?

    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...
  50. M

    Mathematical Reasoning and Writing:

    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...
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