Test Definition and 1000 Threads

  1. tsuwal

    What are test hooks used for in an electric tool kit?

    I just bought a eletric tool kit and this thing came with it: I think they are called test hooks but i just can't figure out what are they for.. I can't find nothing that connects to the top hole of that thing.
  2. F

    Alternating Series Test - No B_n?

    Homework Statement Ʃ(-1/2)^k from 0 to infinity. Homework Equations Ʃ(-1)^k*B_n from 0 to infinity where if the series converges 1. lim of B_n as n goes to infinity must = 0 2. B_n must be decreasing The Attempt at a Solution It doesn't look like there is a B_n in the original equation...
  3. R

    MHB Improper integrals (Comparison Test)

    Use the comparison test to find out whether or not the following improper integral exist(converge)? integral(upper bound:infinity lower bound:2) 1/(1-x^2) dx Here's my solution for 3),but I think something went wrong For all x>=2 0<=-(2-2x)<=-(1-x^2) that means: 0<=-1/(1-x^2)<=-1/(2-2x)...
  4. C

    Studying for the GRE subject test: physics

    I am going to do the GRE subject test: physics, and I would like to know if any of you have some advises to study for this test, as well as books to use to prepare for this test. Also if you have already done the test it would be helpful to know about your experience.
  5. Fernando Revilla

    MHB Improper integrals (Comparison Test)

    I quote a question from Yahoo! Answers I have given a link to the topic there so the OP can see my response.
  6. J

    Proof of the preliminary test (Divergence test for series)

    Homework Statement Proove \, that \, if \, \lim_{n \to \infty} a_{n} \neq 0 \, , \, \sum^\infty a_{n} \, divergesHomework Equations S_{n} - S_{n-1} = a_{n} \lim_{n \to \infty} S_{n} = S The Attempt at a Solution S_{n} - S_{n-1} = a_{n} \lim_{n \to \infty} S_{n} - S_{n-1} = \lim_{n \to...
  7. Fernando Revilla

    MHB  Use the Ratio Test for Convergence/Divergence

    I quote a question from Yahoo! Answers I have given a link to the topic there so the OP can see my response.
  8. C

    Alternating Series Convergence Test

    According to my calculus book two parts to testing an alternating series for convergence. Let s = Ʃ(-1)n bn. The first is that bn + 1 < bn. The second is that the limn\rightarrow∞ bn = 0. However, isn't the first condition unnecessary since bn must be decreasing if the limit is zero. I...
  9. W

    How Do Manufacturers Test Power Capacitors?

    How do test a power capacitor?
  10. D

    Ratio test for math convergence

    Homework Statement show ## \sum \frac{x^{2}}{(1+x^{2})^{n}} ## converges uniformly on R Homework Equations The Attempt at a Solution I know by ratio test it is absolutely convergent for all x in R. I am guessing you use m-test. However I do not really understand how...
  11. R

    Have you heard about this kind of test of hypothesis

    In one example I saw someone make an argument I haven't seen before. They had 2 confidence intervals for 2 different statistics, and they said that since these two confidence intervals didnt overlap, we could assume that the expected values where different. This made me think of test of...
  12. D

    Was My Prof. Wrong? Temperature & Potency Questions Answered

    1. 2 questions, one asked for the temperature of the water max density and the other one a Potency question which the awnser was 1125... Trying to be funny( hahaha funny as **** ) i wrote 1124,999... as the anwser, since 1124,999...=1125 but my prof. said it was wrong this statement in...
  13. DiracPool

    Can we really ever accurately test SR time dilation?

    The two most famous "tests" for the accuracy of time dilation in SR are 1) the plane that flew around the globe with the atomic clock, and 2) the muon experiments on the mountain. I'm assuming, of course, that all the experimental controls are correct and so are the results. My question is...
  14. Lebombo

    LCT Limit Comparison Test for Improper Integrals

    Learning about the Limit Comparison Test for Improper Integrals. I haven't gotten to any applications or actual problems yet. Just learning the theory so far, and have a question on the very beginning of it.Homework Statement f(x) ~ g(x) as x→a, then \frac{f(x)}{g(x)} = 1 (that is, f(x)...
  15. T

    Work Done by an Insulating Sphere on a test charge

    Homework Statement An insulating sphere of radius 0.240 has uniform charge density 6.50×10−9 . A small object that can be treated as a point charge is released from rest just outside the surface of the sphere. The small object has positive charge 4.10×10−6 How much work does the electric...
  16. A

    Signal Injection Test: What, How, & Expectations

    hi I would like to ask, what is all about a "signal injection test" ? How is it done and what one expects to see ? I ve read about it in some Higgs study/plots CERN has published thanks Alex
  17. O

    Convergence Test (Comparison) Questions

    Hello everyone, I need some help on doing convergence tests (comparisons I believe) on some Ʃ sums. I have three, they are: 1. Ʃ [ln(n)/n^2] from n=1 to ∞. I tried the integral test but was solved to be invalid (that is, cannot divide by infinity). Therefore I believe it to be a...
  18. L

    Test Hypotheses with sample of Binomial RV's

    Hi, I am trying to teach myself how to test hypotheses for any distribution, but am having some trouble. X=number chosen each year θ=Mean number chosen in the population H0: θ=.5 h1: θ>.5 The random sample of n=4 is 0,1,3,3 Test the Hypotheses at α≤0.05 assuming X is a...
  19. 1

    Please help - Efficiency of car engine question Unit test tomorrow

    Please help -- Efficiency of car engine question... Unit test tomorrow Homework Statement A car's engine is only 12% efficient at converting chemical energy in gasoline into mechanical energy. If it takes 18000 N of force to keep the car moving at a constant speed of 21 m/s, how much chemical...
  20. O

    Testing Algorithm for Global Minima of Test Functions

    I'm testing an algorithm to find the global mimina of a function. Can someone give me a few examples of optimization test functions in 2 or 3 dimensions, like the Rastrigin function. I'm hoping to find functions with several local minima.
  21. P

    Proving Convergence of Direct Comparison Test for \sum \frac{3}{n^{2} + 1}

    Homework Statement Show that: \sum \frac{3}{n^{2} + 1} converges from n = 1 to ∞ Homework Equations If Ʃbn converges, and Ʃan < Ʃbn. Ʃan also converges. The Attempt at a Solution \sum \frac{1}{n^{2}} converges \sum \frac{3}{n^{2} + 1} = 3 * \sum \frac{1}{n^{2} + 1}...
  22. L

    Determine if a test procedure is unbiased

    I am asked to determine if a test procedure is unbiased. I have the power function and all of that, but I can't figure out what I need to do to determine if the test is unbiased or not. I am guessing I need to find the expected value of the power function or something, but what is that...
  23. D

    Counting U Test for Mann-Whitney Test & Finding Z Value

    Could some one tell me how to count a U test? I can´t find it anywhere! So I know you rank the values from smallest to biggest across each sample (if that makes any sense to you) and then you count the ranks together and use the following equation: U = n(1) * n(2) + ( n(1) * [ n(2) + 1])/2 - R...
  24. D

    Graphing results of performance test and finding area under curve

    Problem statement, I am calculating the time it takes for my motorcycle to reach 55 miles per hour, through its engine Horsepower, Torque, transmission gearing, and sprocket gearing.(chain driven) I am using the equations: F=[mass/g]*[dV/dt] dt=[mass/g]*[dV/F] t=∫[mass/g]*[dV/F]...
  25. F

    Test charge in electric and magnetic field

    Consider an proton placed at the origin; a uniform electric field exists along the Y axis, and a uniform magnetic field along the Z axis. In what direction does the proton accelerate? My intuition is that it accelerates along the X axis, normal to both fields, but I'm not sure. Can anyone...
  26. D

    Pearson chi-squared test (χ2): differences?

    So, as far as I know, there are two χ2-tests: "test for fit of a distribution" & "Test of independence" How big of a mistake is it to use the one instead of the other in an exam for example (of course all exams are all different to some degree, but generally)? The only differences I can...
  27. L

    How are brain-reward thresholds measured by an ICSS test?

    I'm reading a scientific article about the effects of alcohol addiction and withdrawal on brain-reward functioning in rats (file attached to this post) and am having some trouble understanding the methods used. How are brain-reward thresholds measured and monitored through ICSS? (Intracranial...
  28. S

    When Is the Divergence Test Applicable for Series?

    Homework Statement Not really a problem, more of a general question. When exactly can you use the Divergence test. Does it only work on both series and sequences?Homework Equations The series Diverges if lim ƩAn ≠ 0 The Attempt at a Solution If you take the lim of the series n^3/2n^3 ≠ 0 there...
  29. T

    Comparison Test problem with infinite series

    Homework Statement I need to use the Comparison Test or the Limit Comparison Test to determine whether or not this series converges: ∑ sin(1/n^2) from 1 to ∞ Homework Equations Limit Comparison Test: Let {An} and {Bn} be positive sequences. Assume the following limit exists: L =...
  30. F

    Ratio test (convergent or divergent?)

    Homework Statement ∞ Ʃ n / 2^n n=1 Homework Equations ratio test lim |a(n+1) / a(n)| n->∞ The Attempt at a Solution I have the answer and the steps its just there's one part I am confused on, first I just apply n+1 to all my n terms, which gives me, ∞ Ʃ...
  31. J

    Understanding the Kolmogorov–Smirnov test

    Dear all, I am using some software to perform a two-sample Kolmogorov–Smirnov test. Specifically, I am testing the compatibility of two histograms. The function returns a single number that is 1 for a perfect match (when I compare the histogram to itself) and somewhere between 0.05 to 0.25...
  32. R

    A proof for Gauss' test for convergence

    Homework Statement if \frac{a_n}{a_{n+1}}=1+\frac{p}{n}+β_n and β converges absolutely, then at the infinity the sequence a is of the same order as \frac{c}{n^p}. Homework Equations Basic convergence test(Cauchy and d'Alembert's tests) The Attempt at a Solution I find this question...
  33. M

    Series Test for convergent and divergent

    Homework Statement Ʃ √n/(ln(n))^2 from n=2 to ∞ Homework Equations Series Test for convergent and divergent The Attempt at a Solution I tried doing ratio test and gotten [√(n+1)*(ln(n))^n] / [(ln(n+1))^(n+1) * √n] to find the limit, do...
  34. S

    Please answer i have a test in 11 hours

    In a parallel circuit, I know that the brightness stays the same even if you add more bulbs because the voltage is the same as the battery's in each bulb. But, if when you add resistors the REQ is lowered, doesn't that mean the current drops? And if the current drops and the voltage stays the...
  35. T

    How to Use Comparison Test for Convergence?

    Homework Statement Is the series convergent or divergent? \sum_{n=0}^{\infty}{\frac{1}{\sqrt{n+1}}} Homework Equations I can use any test but wolfram alpha says that it is divergent by comparison test. The Attempt at a Solution How do I apply comparison test? I can compare it to: \sum _{...
  36. Y

    Question about the Integral Test

    So this is my first post, I was wondering can you explain the first two examples of this page? http://www.math.ubc.ca/~rathb/mar_6_p_4.jpg What I don't understand is why, if there is a horizontal asymptote at p = 0.99 < 1 on first example, it diverges to infinity but in the second...
  37. B

    Question about root test for series

    Homework Statement Can you if given a sigma notation for an infinite series Ʃ 2^n/(4^n+1) rewrite as, Ʃ 2^n/(4^n+1^n) then doing the root test can you lim n→∞ n^√abs((2/(4+1))^n) which equals 2/5, and 2/5<1, therefore can i conclude that the series above converges? Sorry...
  38. N

    How Do You Calculate Electric Potential for Spherical Shells?

    Electric potential probelm! HELP PLEASE TEST TMRW! Two uniformly charged spherical shells of radii R and 2R with identical surface charge densities σ are along the x-axis. The surface of each of the spheres is located a distance R from the origin O Define the potential at ∞ to be zero. Along...
  39. W

    What is the next step for determining convergence or divergence of this series?

    Homework Statement determine either absolute convergence, conditional convergence, or divergence for the series.Homework Equations \displaystyle \sum^{∞}_{n=1} (-1)^n \frac{6n^8 + 3}{3n^5 + 3} The Attempt at a Solution I cannot use the alternating series test since the function is increasing...
  40. W

    Convergence of tan(1/n) using Direct Comparison Test

    Homework Statement Use any test to determine whether the series converges.Homework Equations \displaystyle \sum^{∞}_{n=1} tan(1/n) The Attempt at a Solution Direct Comparison Test tan(1/n) > 1/n By integral test: 1/n diverges thus, by dct, tan(1/n) diverges.
  41. T

    What is the purpose of the phase shift test in a black box?

    Homework Statement So in the future, I will have to find out what is inside a black box: Homework Equations The Attempt at a Solution Here is the solution to it: http://drunkenengineer.tripod.com/Year1/ele202/blackbox/blackbox.html The issue is that I'm having trouble understanding why the...
  42. dlgoff

    My daughter's 4th Dan Black Belt test

    I returned home yesterday from North Carolina and wanted to give an update via some pics. In the motel the evening before her test. https://imagizer.imageshack.us/v2/393x295q90/r/526/img0194hi.jpg Doing a little tune-up at the Masters dojo the morning before the test...
  43. C

    MHB Ratio Test Questions/ Series Convergence

    I am trying to determine convergence for the series n=1 to infinity for cos(n)*pi / (n^2/3) and I am doing the Ratio Test. I found the limit approaches 1 but is less than 1. Does this mean that the limit = 1 or is < 1? I am somewhat confused since this changes it from inconclusive to convergent.
  44. M

    Series Test for convergent and divergent

    Hello. I.m struggling to understand how to test for convergent and divergent. ∞ Ʃ (n/(n+1))^(n^2) n=1
  45. A

    If I have a metal mesh can I test it's resistance with a multimeter?

    Is it possible to measure the resistance across a wire mesh with a multimeter? Thanks.
  46. H

    When can you not apply the alternating series test?

    Homework Statement I have a series Ʃ(1 to infinity) ((-1)^n*n^n)/n! Homework Equations The Attempt at a Solution apparently you cannot use the alternating series for this question, why is this? It has the (-1)^n, what else is needed to allow you to use the alternating...
  47. R

    Drop Test Results: 24.75lb Weight at 1ft Height

    im trying to calculate the drop force of falling object. we do drop test at my work and believe the figures are wrong. we drop a 24.75lb weight from different heigths to check parts . they have it now set that dropping the given weight from 1 ft only produces 24.75 ft/lb force and they add 24.75...
  48. M

    Choosing the Best Test for Exponentiality for Sample Size of 150

    Hi, If I have a sample of 150 data how to chose between tests of exponentiality? I mean is there any way to find the most appropriate test for my case judging on my data number,or maybe skewness, kurtosis, etc? Or there are 2 or 3 frequently used tests (Pearson maybe) which are most used...
  49. W

    Does the Limit Comparison Test Work for Divergent Integrals?

    Homework Statement use limit comparison test. Homework Equations \displaystyle\int_2^∞ {\frac{1}{\sqrt{x^2 - 1}} dx} The Attempt at a Solution I have tried usin 1/x as the comparison function, but when applying the test it comes out to 0, not an L -> 0 < L < ∞
  50. H

    Help with data from tensile test

    Hi Just got the data from a tensile strength test on a axle we did in school. Before it broke: http://i.imgur.com/1ddrZ7j.png The data : https://www.dropbox.com/s/xf5m8m8gyco561n/data.txt column 1: the displacement in mm column 2: the force in kNI'm supposed to plot a stress strain diagram...
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