Hard Definition and 1000 Threads

  1. I

    What is the Integral of e to the Power of 3lnx and e to the Power of 3x?

    Homework Statement \int e^{3lnx} + e^{3x} dx Homework Equations The Attempt at a Solution Not sure if I should use an e substitution or if I'm forgetting some easy e rules... Any help appreciated.
  2. 0

    How Can I Successfully Clone a Hard Drive?

    Hi everyone, i'm new here. i want to know how to clone the hard drive of computer. which software is the best? i heard about norton ghost but is an alternatives? And is it possible to find a step by step procedure to do this. Than you very much 042012
  3. S

    Identifying Biasit gets hard to determine

    [Question] Identify what, if any, bias is found in each of the following sampling scenarios. Explain your answer for each one. a) Selecting some residents of a building to participate in a survey of recycling options based on the last digit of their phone number b)Deciding whether to...
  4. S

    Arc Length of Ellipse, Hard Integral

    Homework Statement Find the arc length of the ellipse or deformed circle. r^2=x^2+(y/β)^2 r=radius β=dilation constant k="random" constant Homework Equations The Attempt at a Solution I suspect it's impossible but I can't prove that. After working it out I got stuck with these...
  5. V

    Factors affecting how hard a man has to pull on a pulley

    A question has arisen (not homework) showing two pulley systems and a box being pulled up with a man pulling each. The question asks who has to pull hardest. On one of them (A) the shafts (supporting the rope) are smaller whilst on the other (B) they are larger. The correct answer is that the...
  6. zoobyshoe

    Do People Regret Working Too Hard at Life's End?

    "I wish I hadn't worked so hard." Top Five Regrets of the Dying http://www.guardian.co.uk/lifeandstyle/2012/feb/01/top-five-regrets-of-the-dying
  7. M

    Medical How can I improve my sleep before important events?

    I'm sure there are some of you (most, if not) who've experienced this, but mine's really bad. When I have classes for the next day, I could not sleep the night before because I'm thinking too much, ironically it's about being not able to sleep. During the days where I have no classes, I seem...
  8. S

    Integrating Hard Integrals: No Closed Form Solution

    Please see the attachment. Under the given range of parameters the integral converges, but I can't find a closed form solution. It seems one has to integrate very special functions other than simple Beta, Gamma, Error functions etc..
  9. N

    Programs How hard is it to get an industry job with a Physics Phd?

    Hi everyone. I'm a senior undergrad and about to obtain a bachelors in physics from a top US university. I specialized in solid state physics and am doing my undergrad honors thesis in graphene synthesis and characterization. I want to eventually work in the semiconductor industry or with...
  10. L

    Going to Mars as a private company - How hard would it be?

    Title says it all. I was debating this with some friends that if I came into a nice hunk of funds, just how hard would it be to finance a two man ship to go to Mars?
  11. A

    Programs Besides the mathematics, how hard is an engineering degree?

    I have read countless articles, threads, discussions, you name it, about engineering, because I have always been back on forth on whether I will succeed at it or not. I have been going to a state university for two years, and am starting at the technical institute this summer. Deciding between...
  12. K

    Hard conceptual probability problem

    Homework Statement Hello, i encounter a conceptual probability problem that I think i have come into confusio. The situation is - There are 3 Blue ball and 1 Red ball in a bag (BBBR), while there are 4 Green balls in another bag (GGGG) If one of the balls is taken from bag A to bag B...
  13. C

    Having a really hard time understanding Lenz's Law

    I have read my text and watched youtube videos but this just won't register in my brain. Does anyone have a much simpler way to explain it or know of another source that can help. Specifically, how would one use it to figure out the direction a current is going given a variety of different...
  14. P

    Is Probability Really Easier Than Calculus?

    It seems like everyone I know believes that probability is much easier than Calc, but I believe that's a subjective point of view. I know that Calculus has various levels (i.e. I,II,III), but is it really all that much more difficult than probability? How many different 'levels' of probability...
  15. A

    How to create a hard graph easily?

    http://im16.gulfup.com/2012-03-07/1331125411751.png I know the answer is (E) , but HOW ?
  16. N

    Help Covariant Derivative of Ricci Tensor the hard way.

    [SIZE="5"]I am trying to calculate the covariant derivative of the Ricci Tensor the way Einstein did it, but I keep coming up with \nabla_{μ}R_{αβ}=\frac{∂}{∂x^{μ}}R_{αβ}-2\Gamma^{α}_{μ\gamma}R_{αβ} or...
  17. C

    Why does my laptop freeze when I shake it while watching a movie?

    My laptop is equipped with hard drive shock protection. If I am watching a movie and the accelerometer senses a perturbation (me shaking the computer) the image is immediately frozen, but there is no interruption in the sound. Why is this the case?
  18. C

    Programs Liberal Arts major and hard science Phd?

    Is it possible, or worth the trouble? A little background info: I'm currently a freshman at a small liberal arts college. I didn't give much thought to anything outside of the humanities when I chose to come here because I wanted to go to law school, which doesn't require any prerequisites. I...
  19. S

    Data delete after power off from my external hard drive type my passport 500 g.b

    thanks to read my message after transfer my document and plug out my external hard " my passport 3.0 500 g.b " all data delete , please help me
  20. Blandongstein

    MHB Yes, the 13's should be 12's. My mistake.

    \[ \int \sin^{12}(7x) \ \cos^{3}(7x) \ dx \] Ho do I solve this Integral? What can I substitute??
  21. P

    Two hard physics problems (Projectile motion and gravitation), for me

    Homework Statement Please refer to the figures. (The first one is multiple-choice, the latter is structured). Homework Equations For the first problem: u = √(2gH) x = uxsinθt + \frac{1}{2}gsinθt2 uycosθt = \frac{1}{2}gcosθt2 and maybe others u = initial velocity x = x-displacement...
  22. D

    How hard is it to switch fields?

    How hard is it to switch fields in science? For example, say you do your Ph.D. in an area of theoretical physics and are very successful, but cannot find further funding at some point (can't land a postdoc in your chosen field, no professorship offers, denied tenure, etc.). How difficult would...
  23. F

    How to prepare for graduate school in mathematics?

    Hi, I am a sophomore and I recently dropped Graduate Complex Analysis. I was just missing something. The solutions to the questions on the problem set were not capable of being formed by me. This being said, I am wondering if it is still possible for me to attend graduate school for...
  24. I

    Optimizing V=SEH: Solving Really Hard Related Rates Problem | dH/dt = -7/36

    Homework Statement Homework Equations The Attempt at a Solution V=20 S=6 E=2 H=20/12 (from V=SEH?) \frac{dS}{dt}=-.2 <--- + OR -? \frac{dE}{dt}=.3 <--- + OR -? V=SEH Product rule for 3 variables: \frac{dV}{dt}=SE\frac{dH}{dt}+EH\frac{dS}{dt}+SH \frac{dE}{dt}...
  25. J

    Challenging Integral: Solving for P(cos(x)^3)/(x^6+1)

    Hi guys I'm wondering how shall I solve this primitive/integral \int\frac{\cos^3 x}{x^6+1}dx I really don't know how to start... which substitution shall I take or if I shall solve it by parts... Any hints or tips will be very appreciated Thanks in advance
  26. G

    Is Hard Work More Important Than Natural Talent in Achieving Success?

    I decided from the start of this year i would work harder and study more maths not that I am bad I am actually very good for a 14 year old turning 15 because i want to be a theoretical physicist one better than einstein but no matter how hard or how long i study maths or work on it it always...
  27. H

    Is A-Level Physics Necessary for Engineering Programs?

    Now you're all mostly physics heads on this forum, so it's important to consider than I understand about 1/75th of what is said on this forum. I love physics, I find it fascinating - but I went to this consultation meeting thing and I was basically told that unless I'm a maths freak I'll...
  28. Z

    What fuels our motivation to achieve success?

    Scientifically, we are just a chemical process on the the surface of a giant rock. The only reason why we do what we do is because "It feels nice". All those long hours at the university and studying. What does it ultimately accomplish? This video explains further http://youtu.be/QK0rsh7WeYY...
  29. L

    Studying Career, def. of studying hard, knowledge gaps etc.

    Hello all, Firstly, sorry for the long post, I was just wondering if someone is in a similar position and would like to hear their thoughts and how they deal with certain things. If it is too long, just skip to the questions I have under each paragraph. I was never spending much time...
  30. Fredrik

    Is integration theory supposed to be this hard?

    ##\newcommand{\dmu}{\ \mathrm{d}\mu}## I'm using Friedman to try to learn some integration theory. I got the impression that all books start by defining integrals of simple functions in the same way, and then there are several different ways to generalize the definition to more interesting...
  31. B

    Courses How hard are Electrical Engineering graduate courses?

    I don't really have a background in EE, I have a background in Computer Engineering Technology. It's a lot less theoretical and more of a hands on degree. I'm just wondering if I'll have a hard time in graduate level courses in EE. I have a strong programming background, know my way around...
  32. D

    How to Find z in a Complex Algebra 2 Problem?

    x = 3^6 * 2^12 y = 3^8 * 2^8 x^x * y^y = z^z for some integer z Find z. I took the log of both sides, but don't know what to do next (I'm not even sure taking log of both sides will produce anything).
  33. A

    Studying Taking calculus and have hard time understanding the textbook. Help .

    Taking calculus and have hard time understanding the textbook. Help please. My textbook is called Calculus:One Variable by Salas (10th Edition) I'm at University of Toronto in Canada. My course is named MAT137. A lot of students in my course don't read the textbook. They only do exercises...
  34. T

    Can Grade 12 Trig Questions Be Too Challenging?

    Hard Grade 12 Trig. Questions :( Homework Statement http://img831.imageshack.us/img831/8389/daumequation13263429629.png Homework Equations No equations are required. The Attempt at a Solution http://img845.imageshack.us/img845/9519/34851996.png...
  35. S

    Using an external hard drive for storage space and programs

    I have a laptop and I'm running Windows 7. I recently downloaded AutoCAD and some other CAD software and I needed extra storage space on my laptop, so I bought an external hard drive. I was wondering if there was any way I could reinstall any programs onto the external HD to clear up some...
  36. T

    Image processing problem (counting is hard )

    Hiya! Long time registrant, have not used these forums is years though... Anyhow, the problem I have is that I need to collect data from a very large number of images that are essentially horizontal lines on a page. I've attached a sample here, which has been processed to find the edges of...
  37. O

    Non Constant Hazard Rates - Calculating the modal failure rate of hard drive

    Hi, I'm currently trying to work through a problem about calculating the most likely time for a hard disk to fail: Hard disks fail with a probability per unit time: \alpha (t) = \alpha _0 t where \alpha_0 = 0.5 years. I know that the answer is t_{modal} = \frac{1}{\sqrt{\alpha_0}}, but am...
  38. R

    Engineering Calculate RLC Circuit Values: R1, R2, and Xl | Step-by-Step Guide

    Homework Statement An RLC circuits consists of R1 a 10-ohm resistor, R2 a resistor that takes 50 W, C1 a capacitor with 5-ohm reactance, and L1 an inductor that takes 100 var. Find the value of R1, R2, and Xl (inductive reactance).Homework Equations P = (I^2)R Xc = 1/(2∏fC) Xl = 2∏fL Z =...
  39. 1

    Hard to find bubble rise paper/bubble shape determination

    Hi all. I'm looking for a paper that I've seen referenced in a couple of articles I've been reading. The paper is O. M. Kiselev, Determination of gas-bubble shape in axisymmetric flow of fluid, Zh. Prikl. Mekhan. Tekh. Fiz., No. 3 (1963). The English name of the journal is Journal of...
  40. C

    Hard power series and initial value problem question

    Homework Statement We know that y = Aex is the solution to the initial value problem dy/dx = y; y(0) = A. This can be shown by solving the equation directly. The goal of this problem is to reach the same conclusion using power series. Method: Let y be a solution to the initial value...
  41. C

    VERY HARD randomized algorithm/hash function question. PLESE HELP

    I have been trying to solve the problem in part (vi) for almost a whole week, but still not able to solve it. Please read the attachment before proceeding. I was able to show that, using part (iii), we can construct a deterministic program S from P. Then S gives the same outcome as G for the...
  42. J

    I'm having a hard time determining what this factor group looks like

    Ok, so to form the factor groups, let's say G(+)H/J, you take every element of G(+)H and left multiply by elements of J. Well elements of G(+)H look like (g, h) and elements of J look like (g, e_2)...so elements of the factor group look like (g_i, h_i)(g_n, e_2) = (g_i*g_n, h_i) Am I...
  43. R

    X ray questions:What material is suitable in windows for hard X-rays?

    What material is suitable in windows for hard X-rays? What material would you choose as reflective coating of X-rays mirrors for radiation at 200 eV? Why?
  44. T

    What are the Dimensions of a 2.5' Hard Disk Drive?

    Hi there, does anyone knows the overall dimension for 2.5' hard disk drive?including all the components inside. who has the complete dimension? tq =)
  45. W

    How Can I Solve This Complex Differential Equation?

    Hi everone, i am trying to Solve the N.-St.-equation for a special problem - i was able to solve my equation for the 2 velocity components - the 3rd velocity component i seperetated - one term of the Seperation i was able to solve with a Bessel function, the 2nd term now looks like this...
  46. N

    Extremely hard vectors/geometry problem: Find the centre of a sphere

    Homework Statement Plane α: x-2y+z=2. Plane β: 2x+y+z=5 Point P= (0,1,4) is on the line of intersection, with directional vector L, between the two planes. A sphere is touching plane alpha at point A and plane beta at point B. Show that PB is perpendicular to L and the normal vector of...
  47. F

    Solving a Hard Energy Physics Problem: Pendulum Cut Question

    Homework Statement http://img694.imageshack.us/img694/1115/pendulumcutquestion.jpg Please ignore the blue pen. Homework Equations Ek=1/2 mv2 Ep=mgh The Attempt at a Solution Basically I looked at the problem firstly as the pendulum has reached the lowest point, therefore...
  48. T

    Why Does a Hard Boiled Egg Spin and Raw Egg Won't?

    why would a hard boiled egg spin and raw egg won't if made to spin on a flat surface?
  49. C

    Solving Trigonometric Identities (A bit Hard)

    Alright, well I am having a difficult time getting these equations to equal out! I keep hitting trouble and have hit a road block. Here is the problem... csc(x)+cot(x) = cot(x)csc(x) tan(x)+sin(x) I am just going to work on the LEFT PART of the equation. 1 + cos(x) sin(x)...
  50. J

    Complex Line Integral (not too hard)

    Homework Statement ∫dz/(z4+1) integrated over the curve C1(1+i) Homework Equations The only thing we learned in this chapter is Cauchy's integral formula, so I'm assuming that comes in somehow. The Attempt at a Solution ∫dz/(z4+1) = ∫dz/(z+1+i)(z+1-i)(z-1+i)(z-1-i) Not bad...
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