Writing Definition and 688 Threads

  1. E

    Fortran Fortran OpenMP parallelization and writing in multiple files.

    Hello. I'm attempting to write some data in different files (each thread write in each file), but I'm getting an error saying: 'File already opened in another unit'. I'm using the function OMP_get_thread_num() from OpenMP library in order to open individual files in individual threads. !$OMP...
  2. T

    Writing down an explicit bijection

    Homework Statement Let X= \{a,b,c\} and Y= \{d,e\}. Write down and explicit bijection N_{|X×Y|} → X×Y The Attempt at a Solution Well I came up with the easiest method, just giving one value to each member of N_{|X×Y|} so I was just wondering whether there is another way of doing it not by...
  3. M

    Writing Volume as a Function of Height for an Open Box

    Homework Statement An open box of maximum volume is to be made from a square piece of material 24 centimeters on a side (24-2x) by cutting equal squares from the corners and turning up the sides. The table shows the volumes V (in cubic centimeters) of the box for various heights, x (in...
  4. G

    Writing questions out is better than asking them

    i used to believe that i was getting a second rate physics education because i wasn't attending any classes and the only way i could get answers to problems was to ask them here. so a little while ago i went to my first public lecture on physics since i started studying physics heavily. some...
  5. U

    How to Express \(\frac{1}{e^{z}-1}\) in \(u+iv\) Form?

    This is related to another post of mine. How would you go about writing \frac{1}{e^{z}-1} in u+iv form? Usually multiplying through with the complex conjugate gives you the desired form, but here I'm not sure that it works. Any suggestions?
  6. B

    Writing out MHz Band and the kHz Band?

    I need some help with FREQ. on the MHz Band and the kHz Band? If I am on a Radio that displays the FREQ 909.5 MHz I know I would write this out as 909,500,000 Hz and this is 9 Hundred and 9 Thousand 5 Million Herts Am I right?
  7. 1

    Writing a differential equation to describe cooling

    Homework Statement Newton's Law of Cooling states that the temperature of an object changes at a rate proportional to the difference between the temperature of the object itself and the temperature of its environment. Suppose the ambient air temperature is 70*F and that the rate constant...
  8. J

    Writing Computations Clearly In Proofs

    Here's a quick question concerning writing clearly in proofs. I am revising and refining some of my proofs [this is for a self-study], and I across a problem where I had to prove that f: G->G defined by f(x)=axa-1 is a automorphism. To show it has the homomorphism property, I had to do some...
  9. R

    Has anybody taken part in online collaborations writing a scientific paper ?

    Has anybody taken part in online collaborations writing a scientific paper ? experiences ? Just what the title says really. I am collaborating with a programmer and a mathematician (myself biophysics) on a computational neuroscience paper. Ill be lead author as the primary concept is mine...
  10. D

    Writing Out Equations with a Modulo Function

    Hi, I'm trying to write out a set of equations I was using in an excel worksheet and am unsure how to represent a modulo function. For example, is there a proper way to write out the following excel formula in mathematical terms? =MOD(280.4+X*(36000.7 + X*0.0003032),360) *Where X...
  11. J

    Punctuation in mathematical writing

    Recently I went through a bunch of my old solution sets and realized that I've been quite sloppy with my use of punctuation; in particular, examining the quality of my writing in solution sets over a period time, it appears that the lack of proper punctuation is getting more and more pronounced...
  12. A

    Writing the Modulus of f(z) in Terms of lzl

    For expressions like: f(z) = (1+z2)/(1+z4) how does one write the modulus of that in terms of lzl?
  13. nukeman

    Help: Writing the 4 quantum numbers for each of the 8 electrons?

    Homework Statement An oxygen atom has a total of 8 electrons. Write the four quantum numbers for the each of the eight electrons in the ground state? I can't seem to figure this out. I know this... O = 1s^2 2s^2 2p^4 But from that, I don't know how to finish the question...
  14. H

    Writing Finite Element Code for Structural Analysis

    Structural Analysis-Writing Finite Element Code, Dear all, I have written a code ( in fact it is a software) for 3D finite element structural analysis. While developing the code I found that assembling global stiffness matrix is quite complicated. The complication is even more when we...
  15. D

    Writing Linear Differential Equations as Matrix Differential equations

    Homework Statement Be able to write a system of Linear homogenous differential equations as a matrix differential equations. Homework Equations The Attempt at a Solution I have uploaded the work and original problem. My question is did I properly answer this question?
  16. R

    Need help with strategy for a simple game for a book I am writing:

    I hope this is the right forum to put this in. This is a strategy I am trying to fine tune for a book I am writing about the card game Pinochle. Here are the rules: Two player game - First player to 40 points wins. Game starts 0 points to 0 points. Players alternate turns. One...
  17. C

    Need help writing simple Haskell program please

    So for my program I want to input this line of code: addPairs 10 [(2,3),(4,15),(87,92),(23,45)] Where the 10 after addPairs is the minimum distance the pair (x,y) must have in order to be outputted as [x+y] For example : addPairs 10 [(2,3),(4,15),(87,92),(23,45)] would output: [ 19...
  18. D

    Glass amenable to writing with a graphite pencil

    For a while I've used an IREX DR800 e-book reader, and in the course of my experimentations, I have observed that I can actually write directly onto the screen with a graphite pencil, and erase with a cotton t-shirt. I've been trying to find a larger piece of glass which yields similar effects...
  19. 2

    Writing a matrix as sum of a constant * matrix

    Ok I need some help on how I can approach a problem like this. Say that A B and C are matircies and I know the values of each of them. And let x and y be constants (ie: 7 or 2 or somthing like that) What I want to know is can you write A = xB + yC How would you check to see if...
  20. J

    Writing a recursive function to compute the Jacobi symbol

    Write a recursive function to compute the Jacobi symbol J(a, n), is defined for relatively prime integers a and n, a> o, \mbox{ and } n > 0 by the formula J(a, n) = 1 \mbox{ if a = 1, } = J(a/2, n)*(-1)^\frac{n^2-1}{8} \mbox{ if a is even, } =J(n \% a, a)*(-1)^\frac{(a-1)*(n-1)}{4} \mbox{...
  21. S

    Engineering Mechanical Engineers: How much writing do you do?

    Hi! Right now I'm in my 2nd year of Mechanical Engineering. The only three ME classes I'm taking are Fluids/Thermo I, Mechanisms, and ME Lab I. I don't particularly like the first two, but I'm doing fairly well in them and they give me something to do. However, the lab is killing me. Every two...
  22. T

    Writing this series as a hypergeometric series

    Homework Statement Write \displaystyle \sum_{k=0}^{\infty} \frac{1}{9^k (\frac{2}{3})_k} \frac{w^{3k}}{k!} in terms of the Gauss hypergeometric series of the form _2 F_1(a,b;c;z). Homework Equations The Gauss hypergeometric series is http://img200.imageshack.us/img200/5992/gauss.png...
  23. C

    Writing Net Ionic Equations: How to Include Physical States and Charges

    Homework Statement When writing chemical formulas in Mastering, indicate the physical states using the abbreviation , , or for solid, liquid, or gas, respectively. Use for aqueous solution. Write the total ionic equation (also known as the complete ionic equation) for the reaction of...
  24. P

    Reasoning and Writing Question, what's your interpretation?

    Homework Statement A student takes a 30-question mathematics exam on which she got n questions correct and m questions incorrect and left k questions blank. If correct answers are worth 4 points, incorrect answers are worth -1 points, and blank answers are worth 0 points, write an equation to...
  25. lpetrich

    Writing Web-Browser Math and Physics Demos

    Have any of you people tried writing math and physics demos that can be run in a web browser? The physics demos would have to be simulations, of course. I myself have done so: http://homepage.mac.com/lpetrich/Chatters/GeometryDemo_GMap.html - Spherical Delaunay triangulation, convex hull...
  26. S

    Linear Independence: Writing vectors as linear combinations

    Forgive me for not writing in latex, but I searched this site for 10 minutes looking for a latex reference and could not find anything on matrices. Also, excuse for the excessive amount of info. Homework Statement Determine whether this list of 3 polynomials in P1: p1 = 1+3x p2 = 1+2x...
  27. G

    Writing 4 Quantum Numbers for Electron in 3D Orbital

    what are the different ways to write four quantum numbers that designate an electron in a 3d orbital
  28. C

    Comp Sci How Should I Implement the UserID and Password Generation in Java?

    Homework Statement This is my assignment: (Sorry, it's a little long) You are required to write a UserID Java class to be used when generating and storing the user id and password for a new user of a system. At a minimum, each UserID object should store a first name, last name, user id, and...
  29. B

    Graph of a Differentiable Function with f(2)=0 and Opposite Derivative Trends

    Homework Statement Sketch the graph of a differentiable function f such that f(2)=0, f' < 0 for -infinity < x < 2, and f' > 0 for 2 < x < infinity. Homework Equations The Attempt at a Solution I have answered this question correctly, but what interested me was that in the...
  30. L

    Writing Tensor Equations in Matrix Form

    I'm trying to express the tensor equation F'^{\mu\nu}=\Lambda^{\mu}_{\sigma}\Lambda^{\nu}_{ \rho }F^{\sigma\rho} in matrix form. Here the indices range from 0 to 3, so we need 4 by 4 matrices. Let F', F, and \Lambda be the matrices associated with the tensors appearing in our equation. Which...
  31. Z

    Writing Mathematical Formula in MS Word

    Homework Statement I'm writing up a mathematics-based assignment and I want to type some formula into a MS Word document. I'd appreciate if anyone could let me know how to go about this. Thank you. Homework Equations The Attempt at a Solution
  32. R

    Writing shear and moment equations for a simple beam problem?

    Im trying to generate a simple beam program in mathcad and am having trouble with the integrals. Attached is what I have so far:
  33. R

    Writing shear and moment equations for a simple beam problem?

    I am trying to write shear and moment equations in mathcad for a simple beam problem. Any help would be greatly appreciated. Thanks
  34. T

    Writing a Matrix: Tips & Suggestions

    My apologies if this is in the wring place, but is there any way that I can write a matrix out on this forum? Maybe set up a table in excel or word and copy over? Any suggestions?
  35. D

    Is There a Better Way to Phrase This Sentence About Digital I/O Modules?

    Does this sentence make sense and is there a better way to say it? "Digital I/O modules have a variety of operating voltage range. " what I'm trying to say is that there are different digital IO modules and each has a different operating voltage range rating.
  36. A

    MATLAB Help with writing a matlab code

    ?hi, im trying to write a code that should do this- create a random sized zeros vector create a random size ones vector i have to do this several times and combine it all(by that order) into one vector that should lookz like- 0000011111001111001... does anybosy have an idea how to do it...
  37. T

    Writing a system of 2 ODEs as a 1st order ODE

    Homework Statement Consider the following initial value problem for two functions y(x),z(x): 0 = y''+(y'+7y)\text{arctan}(z) 5z' = x^2+y^2+z^2 where 0 \leqslant x \leqslant 2,\; y(0)=1.8,\;y'(0)=-2.6,\;z(0)=0.7. Rewrite the system of ODEs in standard form using a suitable substitution...
  38. W

    Writing a recursive definition of the set permutation function

    (Apologies for the lack of LaTeX formatting - I usually do my typesetting with MathType, but I only have Microsoft Equation Editor on this computer which doesn't have LaTeX export). This isn't a homework question, but is problem I've discovered I'm facing after diving into another problem, but...
  39. J

    Writing mathematical proofs has greatly improved my life

    After 1-2 years of writing formal math proofs in undergraduate school, I now speak and write much more eloquently than I used to. Now, before uttering or writing a statement, I take a quick pause to ask myself whether it's logically valid; it's unambiguous; it's relevant and sequentially...
  40. N

    Writing Optical Fields: An Explanation by Niles

    Hi When the dielectric function of a system is time-invariant, solutions of Maxwell's Equations are separable and they are usually written as (I only write the E-field) E(r, t) = E(r) \exp(-i\omega t) Now, in my book they write an optical field as E(t) = E_0\exp(-i\omega t) +...
  41. S

    Writing an expression in summation notation

    How would I write 1 + n + n(n - 1) + n(n - 1)(n - 2) + ・・・ + n! in sigma notation? If it's possible.
  42. C

    Need an Easy Equation Editor for Writing Papers? Look no Further!

    Is there a good free/cheap editor for easily/rapidly writing equations? I need to write 3+ papers in the next 2 months and they all have a lot of matrices and equations with indices and all those things that take forever to enter in using MS Word. I hate spending hours on entering that stuff...
  43. Simfish

    Best alternate Tablet to an iPad for writing math or physics equations?

    I'd preferably want something that could replace scratch paper. The iPad's stylus is far too thick for comfortably writing up math equations. Thanks!
  44. Char. Limit

    News Iran Sentences Canadian Programmer to Death for Writing Program

    http://nakedsecurity.sophos.com/2012/01/24/canadian-resident-sentenced-to-death-for-writing-a-computer-program/ I just can't believe this. If anyone wanted proof that Iran's leadership is not in any way civilized, this is it. I feel that something should be done, but I just am not sure what yet.
  45. D

    Writing Vector Equations for positions of toy cars in the form r=a+tb ?

    Homework Statement For the following remote controlled toy cars, write vector equations for their positions in the form r=a+tb (a=initial position vector, b=velocity vector, r= position vector at any time t sec, distances in cm) d. the car is traveling at 15cm/s in the direction 3i+4j...
  46. P

    Error writing recursive function for Bonnet's recursion formula in C

    Bonnet’s recursion formula for Legendre polynomials is P(n,x)=1 for n=0 P(n,x)=x for n=1 and P(n,x)= (2n-1)/n*x*P(n-1,x)-(n-1)/n*P(n-2,x) I tried to write recursive function in C to calculate the value of polynomial for a given n and x float legpol(int n, float x) {...
  47. D

    What is the Exponential Model for Depreciation of a Car's Value?

    Homework Statement A new car that costs $30,000 has a book value of $18,000 after 2 years. a) Find a linear model that represents the value 'V' of the care after 'x' years b) Find an exponential model of V= ab^(x) that represents the value 'V' of the car after 'x' years...
  48. D

    Technical Writing Help: Wiring a Relay Socket

    I'm writing a report and I'm having trouble coming with the right words to describe a procedure. Is there a better way to say "Before wiring PB2 (pushbutton) to the relay, refer to the wiring label on the relay to find the relay socket terminals function." ? What I want to say is learn where...
  49. T

    Writing an absolute value function as a piecewise function

    Homework Statement Write f(x) = |x2-x-12| as a piecewise function. Homework Equations The Attempt at a Solution -x2+x+12 where x>1/2 x2-x-12 where x\geq0 According to the answer book the answers are -x2+x+12 where -3<x<4 x2-x-12 where x\geq4 2x2-5x-3, x\leq1/2 I am...
  50. L

    Are My Sci-Fi Population Estimates Realistic?

    Please forgive me if this fell into the wrong forum. I thought this would be the right place to ask. 500 million years have past since humanity came in control of a device that could send ships at great speeds across the universe, from the edge of one galaxy to the edge of another in weeks...
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