What is Test: Definition and 1000 Discussions

Homework Statement I'd always used the 2nd derivative test for the nature of stationary points. But I came across this equation in one of my exercises, for which the test doesn't seem to work at all. Find the stationary points of: y=(x^2-1)4, stating the nature of each. Homework...

Homework Statement Determine whether the series is absolutely convergent, conditionally convergent, or divergent. ##\sum _{n=1}\left( -1\right) ^{n}\dfrac {n} {n^{2}+1}## the sum goes to infinity. Homework Equations Theorem for absolute convergence. Test for divergence The Attempt...

Homework Statement ##\sum _{n=1}^{\infty }\left[ \left( -1\right) ^{n}\right] \dfrac {\sqrt {n}} {1+2\sqrt {n}}##Homework Equations Alternating Series test, Absolute convergence theorem, p-series, and test for divergence. The Attempt at a Solution The alternating series test tells us that the...

I'm becoming more and more convinced that light isn't the only particle that can interfere with itself, and that the behavior may instead be a function of a particle's level of interaction. The multi-galaxy collision we witnessed not long ago may have been the first time we've had the scale...

Homework Statement (Edit) SERIES of n--> infinity ( -1/n)Homework Equations The Attempt at a Solution First tried ratio test, ended up with 1 so it was inconclusive Then tried integral test, but realized it's not a positive function Now I'm stuck =[ Any hints/advice would be nice

This isn't really homework, but I figure this is the most appropriate place to post this... Please do say if you think there is a more likely place it will get answered - I'm new! Homework Statement I am trying to calculate the muzzle velocity of an air rifle. I can find the time of flight...

my sister asked for help with a science test she had as preperation for her gcse's in this test was a table asking about heat transfer in a vacuum flask some parts of the table were filled in as an example but the question was would heat be lost through A convection B conduction C...

Homework Statement There are 3 parts to this problem: (a) \; \sum^{\infty}_{n=1} \frac{n^4}{4^n} (b) \; \sum^{\infty}_{n=1} \left( \frac{n+8}{n} \right)^n (c) \; \sum^{\infty}_{n=1} \frac{5^n-8}{4^n+11} The attempt at a solution (a) I've used the Ratio test. So, u_n=\frac{n^4}{4^n} and...

I need to test some web based programs, eg. PHP, MySQL, for my dads website but I can't be bothered having to ftp the server everytime I make a slight change to the settings. Is there anyway I could maybe simulate the server and the website on my laptop? I'm running Linux Mint if that's...

Homework Statement The activity of carbon, due to the decay of C14, is 16 disintegrations per minute per gram of carbon. The atomic weight of naturally occurring carbon is 12 u. What is the ration of C14 to C12 in the CO2 of the atmosphere? The half life of C14 is 5730 years. Homework...

Homework Statement Original Cross sectional area 24.63mm^2 original diameter 5.6mm Gauge length 35.07mm Extension length of the point on the graph i have chosen: 0.25mm Force at 0.25mm extension 3500N (or 3.5KN) Homework Equations (F/A0)/(ΔL/L) The Attempt at a Solution I have gone...

Homework Statement This was a question on my test. I had to choose the direction of the acceleration vector for each position. I was wondering if I chose the correct answers. Homework Equations a = gsinθ ƩF_{y} = N_{1S}( normal force) - W_{1E} ( weight force) The Attempt at a...

Homework Statement 2. Show that the function is continuous on the given interval. (a)f(x)= (2x+3)/(x-2) range:(2, infinity) (b)f(x) = 1- sqrt(1-x^2) range:[-1,1] 3. Prove that the following limits do not exist. (a) lim x tends to 0 ( absolute|x|/x) (b) lim x tends to 3 (2x/(x-3))...

hey guys i need help charpy impact test. i have attached my graph with the results we had. Does this seem correct? from the graph how do i determine the transition temperature T1 for the material where T1 is normally defined as the temperature corresponding to 50% of energy change between the...

Homework Statement After reading a few topics on this forum, i just realized that i had misunderstood the sequence v/s series theorem when it concerns the alternating sign. So, i went back to my notes, and I'm surprised to see that there is no mention of a series test. There is only a sequence...

Today sees a key test in the development of the SABRE engine for the Skylon Spaceplane project: http://www.bbc.co.uk/news/science-environment-17864782 What do members think of the prospect of this project? Seems to me that like all promising space ideas it would be great if it could get the...

Hi all, I am simulating torsion tests (after being successful with tension and compression tests). For tension and compression, I got a good comparsion with experimental and behaviour in tension is same as in compression (of course leaving the necking part). For torsion tests, I have...

Ratio Test, SUPER URGENT, help? Consider the series ∑ n=1 to infinity of asubn, where asubn = [8^(n+4)] / [(8n^2 +7)(5^n)] use the ratio test to decide whether the series converges. state what the limit is. From the ratio test I got the limit n-> infinity of [8^(n+1+4)] / [(8(n+1)^2...

I've done 3 wilcoxon matched pair tests and was wondering if someone could give me some advise on the most logical / correct way to report the results. test 1: pre post 1.98 1.56 1.09 2.49 2.18 2.94 1.13 1.29 1.23 2.38 result: Z = -1.438, two tail p = 0.138 So I was...

I will do research on the vertical single strut. i want to ask if there is something interesting to study?

Series Comparison Test, URGENT help? Each of the following statements is an attempt to show that a given series is convergent or divergent using the Comparison Test (NOT the Limit Comparison Test.) For each statement, enter C (for "correct") if the argument is valid, or enter I (for...

I scheduled to take this April 28. Other than the following links, do any good study guides exist for it? For abstract algebra, I was thinking about skimming through my textbook and making note of the important theorems. Any recommendations would be appreciated...

http://www.nytimes.com/2012/04/20/world/asia/india-says-it-successfully-tests-nuclear-capable-missile.html http://www.bbc.co.uk/news/world-asia-india-17765653 There is some confusion here in India in the media as to what is meant by ICBM and whether a missile with a range of 5000 km...

When picturing electric fields, they are always based on a positive test charge. As you move on to potential difference and electrical currents, it is based more on electrons/negative charge. So, why aren't electric fields and fields lines based on a negative test charge instead of a positive...

Hi, Carry out a chi-squared test for the following table of frequencies of X ∼ Binomial(5,p) variates when (a) p = 0.3 x 0 1 2 3 4 5 Observed 162 346 303 149 36 4 frequency Now I know how to carry out the chi-squared test once I have...

Homework Statement The position of a 2.75x10^5 N training helicopter under test is given by...? vector r = (0.020m/s^3)t^3ihat+(2.2 m/s)tjhat-(0.060m/s^2)t^2 khat Find the net force on the helicopter at t=5.0s Express your answer in terms of ihat, jhat , and khat . Express your...

I'm given the following: 3/(n(2^(n-1))) I have to determine convergence using the limit comparison test. I've proved its convergent using the ratio test but am struggling with which term do I divide the above for the limit comparison test. Help?

Hello! I was working some practice problems for a Calc II quiz for Friday on the alternating series test for convergence or divergence of a series. I ran into a problem when I was working the following series, trying to determine whether it was convergent or divergent: Homework Statement ∞...

I am part of a CubeSat team at my school, and one job that I'm currently tasked with is figuring out how to build a transmitting/receiving system that will fit into our satellite. As a result, I am wondering if anyone knows if there are any good, affordable devices that will let me basically...

Homework Statement I've seen two methods that prove the integral test for convergence, but I fear they contradict each other. Each method uses an improper integral where the function f(x) is positive, decreasing, and continuous and f(x) = an. What confuses me is one method starts off the...

Hi guys, Can anybody help with regards to this question?? Suppose we want to compare the length of hospital stay for patients with same diagnosis at two different hospitals hospital First hospital: 5,8,10,13,21,26,29,32,33,44,60 Second hospital: 10,27,35,44,60,68,73,76,86,87,96,125,238...

I just took a physics test today and there was one problem that I cannot figure out if I did correctly. The problem involves a catapult pictured here: http://i39.tinypic.com/a2t76h.jpg The bar is 2m long and has a mass of 3kg. The rock at the end of it has a mass of 5kg. The spring is .3m from...

I am attempting to investigate to what quantitative degree a physical theory agrees with observations of the phenomena it predicts (specifically, Fraunhofer theory). I want to use the chi-squared test to produce some confidence levels in the measurements made in different sections of the...

Homework Statement So what I was taught was that if the lim of the ratio test is the series is always absolutely convergent. If it is >1 the series is always divergent. But if it is =1 then we don't know. So would that mean that all conditionally convergent series would have a limit = 1? I...

Homework Statement \sum^{∞}_{1}1/n^{n} Homework Equations Direct comparison test The Attempt at a Solution Since the main factor in the equation is the exponent that would be changing as n goes to infinity, I know that from the p series as p > 1 the the series converges. So I know...

Why can there sometimes be a difference observed between them?

Dear all, I am Levy , I am glade to take part into physics Forums, I hope I can share my know with everybody and study from you, Thank You! I test the PET of creep deformation recent days, who has some reference about this aspect. Thank you

OK, so I have a solid year+ to prepare for the math GRE subject test. It's pretty intimidating because I don't know where to begin studying. Does anyone know of a good game plan to approach this test with? If you've taken the test, please share how you prepped for it.

I am trying to prove e^z converges on all C. Here is my attempt. e^z=series(z^n/n!) use the ratio test on the coefficents 1/n! gives lim(1/(n+1))=0, which from rudin means radius of convergence R=1/0 -> R=infinity.

Q. Given that A is invertible , check whether A + A^(-1) is invertible or not ? A. A is invertible . => A^-1 exists ( sorry about not using the powers directly. i am not able to click on the required icon ). Suppose a non trivial solution exists to ( A + A^(-1) ) X = 0 (...

Homework Statement For the sum from n=1 to ∞ (1/(sqrt(n^2+1)), I know you can use the limit comparison test to show that it is divergent but I was wondering if it is possible to compare this with 1/(2n)? I am not sure if 1/(2n) is always less than (1/(sqrt(n^2+1)) within those bounds. How...

Homework Statement Here is the problem: http://dl.dropbox.com/u/64325990/HW%20Pictures/integraltest.PNG The Attempt at a Solution I know it is convergent because it is very similar to 1/n^1.5 which is convergent as well. However what would I compare this with using the Integral Test to...

Here is the scenario: Let's say that two sets of samples (SET 1 and SET 2) are from the same population (N=1000). SET 1 and SET 2 has the same sample size (n=500). SET 1 is composed of doctors only, and their average (mean) price that they are willing to pay for a certain product (a new drug) is...

Hi, there is a proof of the ratio test that I have seen a couple of times here: http://tutorial.math.lamar.edu/Classes/CalcII/RatioTest.aspxI don't know how to use latex, so abs(x) will mean absolute value I am ok with this: abs( aN+1) < r abs(aN) I don't understand where the r2 come from in...

$$\sum\limits_{n = 0}^{\infty}\frac{2\pi^{n+1}M}{(n+1)!}z^n$$ So we get $\lim\limits_{n\to\infty}\left|\frac{\pi z^n}{n+2}\right|$. This converges but I don't see how. z is in C.

Not really a homework question, but it could be. Working on making a burst test chamber and need some calculations that says it is safe enough. Sorry for my poor english, it's not my first language. Homework Statement The setup: First a brass fitting would be fitted inside a chamber, and...

Help with a review question please! Test tomorrow Can you please help with this review question. My test is tomorrow and I am not sure how to do this. Helium cation behaves like hydrogen atom. A particle with kinetic energy of 90.00 x 10^-12 erg collides with a gaseous helium cation in its...

http://www.ebay.com.hk/itm/370583387771?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 I have tested it using a 1.3v battery, Once I have switch "ON" this tester, Let the positive end of battery touch on the square metal of the front panel and let the rear square metal of this tester...

Homework Statement A lamborghini's breaking speed is 6.7 times that of its acceleration. The total time taken to go from 0 to 100 and back to 0 is 13.7 seconds. What is the displacement of the car? Homework Equations Unsure at the moment The Attempt at a Solution So, you divide...

hi everybody.. Homework Statement we gave a force to this system (shwon in image) direction to the left;what will happen to this system (toothed axe) will move to the left or to the right or will be jammed? http://data.imagup.com/10/1146213664.jpg thanks for your help and.