Absolute Definition and 1000 Threads

I was reading this article of wikipedia: Conditional and absolute convergence It says: "An absolutely convergent sequence is one in which the length of the line created by joining together all of the increments to the partial sum is finitely long." Is that a characterization of...

Homework Statement integrate modulus of xcos∏x within the limits -1 to 1/2 P.S I'm not allowed to use acaluculator so graphing and finding out the answer not possible Homework Equations it's using the property of definite integral ∫f(x) dx within the limit from a to b = ∫f(x) dx...

Homework Statement A binary star system has two star of equal luminosity. The apparent magnitude of the two stars together is 11.2, and they are at a distance is 76pcs. How do I work out the apparent and absolute magnitudes of just one star? Homework Equations m=-2.5log(L)...

Homework Statement Determine the domain and find the derivative f(x) = ln|(x+2)/(x3 - 1)| Homework Equations The Attempt at a Solution We can factor x3 - 1 = (x-1)(x2) + x + 1) From this we know that x ≠ 1 or -2 because 1 would be undefined at -2 would cause the function to...

Homework Statement A 1.00m tall container is filled to the brim, partway with mercury and the rest of the way with water. The container is open to the amosphere. What must be the depth of the mercury so that the absolute pressure on the bottom of the container is twice the atmospheric...

I used a Sodin Gravimeter to measure the relative gravity of a building with 14 floors. I am wondering on how I use the relative gravity to find absolute gravity? Information: Height difference of each floor is 3.95m Each floor weighs 106kg For example, on the basement floor, the reading...

We were presented with a task of calculating the temperature of absolute zero experimentally. To do this, we were given a capillary tube with one end sealed. Then we heated the tube up in a bunsen burner and quickly put the open end in some cooking oil. The oil was sucked up as the gas within...

I found that the local minimum of y=x(e^1/x) is (1,e) but can someone tell me why the absolute minimum is also not (1,e) and can someone tell me why this function does not have an absolute minimum? Thanks

Is there really an absolute reference frame?? According to mechanics as we understand today, all reference frames are equally valid in analysing in the universe, whether measurements are taken relative to the earth/sun... However if all reference frames are equal, why can't we take...

I have a question about the ratio test. Suppose it proves inconclusive, we must than use another test to check for conditional convergence - 1) this test has to be associated with an alternating series, such as the Alternating Series Test, correct? (we wouldn't be able to use something like...

Homework Statement I'm currently implementing an algorithm in Matlab, however, I've hit a bump, I'm trying to solve the following system of equations: Known variables = a, b, c, d[complex] Unknown variabls = fs, fd, fv, alpha My problem is what to do with the |alpha| since I can't get...

Homework Statement \sum_{n=1}^{\infty}(-1)^{n+1}\frac{\sqrt{n}+1}{n+1} Homework Equations absolute convergence test The Attempt at a Solution by book says that the series converges because \sum_{n=1}^{\infty}\frac{\sqrt{n}+1}{n+1} converges but they don't show how the absolute...

I need to find the absolute value of b(t): b(t)=a(t)[1+e^{-j2\pi tT}] Here is the answer in the textbook: \therefore \left | b(t) \right |=\left | a(t) \right |\sqrt{2(1+cos(2\pi tT)}2|cos(\pi tT)| However I got a different answer when working it out, and can't understand how they got...

Homework Statement Determine the values of z \in \mathbb{C} for which |z+2| > 1 + |z-2| holds. Homework Equations Nothing complicated I can think of. The Attempt at a Solution For real values this holds for anything greater than 1/2. If I could figure out the boundaries of the...

Homework Statement I was helping my sister with her high school geometry homework, and she had to graph the absolute value function y=lx+6l using two linear equations. The way i did it was different than the way her book showed. Basically, I told her that when removing the absolute value you...

Galilean space-time renounces that use of co-ordinate systems such as x3 and t1 because comparing two space-time co-ordinates such as x3=1,2,3, t1=1 and x3=1,2,3,t1=10 says you are looking at the same point in space 9 seconds apart. This is thought to be naive. But in special relativity, time is...

does particles stop radiating or do particles have kinetic energy at absolute zero?

Hi All, I am confused about what is meant in the mathematical definition for the energy of a signal. Why is it the integral of the magnitude of the signal squared? ∫(|f(t)|^2) How do I deal with the absolute value sign? I do not have much experience with absolute value signs in...

Homework Statement A conducting sphere of 5-cm radius has a surface charge density of 1 pC/m^2. If the medium of relative permittivity is 2. How can we find the absolute potential at a distance of 3m from the center of the sphere? Homework Equations V=Q/4∏εr The Attempt at a...

Find the limit, if it exists. (If an answer does not exist, enter DNE.) lim x→−8 [ 8 − |x| OVER 8 + x ] The attempt at a solution First → abs(x) = -x ; x<0 / x ; x≥0 Therefore, our equation is going to look like 8 − -x OVER 8 + x If approaching -8 from the left, I...

hey~ folks! i'm in trouble with this integral problem. the range of the integral is from -∞ to ∞ and it has x as independent value. and the integrand is a derivative of absolute value in exponential; ∫^{∞}_{-∞} (d/dx e^{-a|x|})dx any idea for the problem??

If an airplane door has an area of 4032 in^2 and the pressure inside the plane is 14 psia (absolute), What is the force on the door when the plane flies at an altitude where the pressure is 2 psia?

Homework Statement Suppose you are given the following inequality -6x+ 4y+ 10z \leq 1203 7y + 15z \leq 1551 x,y,z \geq 0 Find a K > 0, if it exists, such that |x| \leq K, |y| \leq K, |z| \leq K Flyingpig's take on this So I am just going find the max of each x,y,z Let x =...

absolute value help ... i am a bit confused about two things... first: is sqrt(x^2) is the same thing as |x|? if yes then consider a negative no. 'z' ... i had a question like this: sqrt(z^2)...its answer was -z...so i suppose this means that this square root/ square and absolute value thing...

Homework Statement If an electronic scale reads 502.4 g, what is the absolute uncertainty in the mass reading. Homework Equations Not sure The Attempt at a Solution Not a clue, it seems that there isn't enough information given. How am I supposed to figure out the absolute...

Homework Statement Consider a simple first-order linear differential equation, such as y' + \tan x y = 0 With initial condition y(0)=C for some constant C. Find all solutions y which satisfy this differential equation on the entire real line. Homework Equations General method for...

Please be patient with me. Cosmologists compute all the way back to the big bang when there was just a very condensed point of energy from which time, space, whatever else came forth, and now we have -- to be humorous -- a nose in our face that does not fall off even if we sneeze very hard...

Absolute value Quest, urgent Homework Statement a) |x-2| + |6-3x| = 12x Homework Equations The Attempt at a Solution I have a question about y this negetive becomes a positive.. :: Steps :: |x-2| + -3|x-2| |x-2| +3 |x-2| = 12x > this step if i factored out...

I saw some books and say that norm is the absolute value in vector. If it also means absolute value, why don't we use absolute value |\vec{v}| instead we use ||\vec{v}||?

I'm a little confused about solving absolute value equations and why sometimes solutions don't seem to make sense. Take a look at case (ii) on this website: http://www.algebralab.org/lessons/lesson.aspx?file=Algebra_AbsoluteValueEquations.xml I understand the process of solving the...

Hi, I understand for metals the conduction band is usually partially filled. However, at absolute zero, is the conduction band empty (for metals)? I'm asking this because as far as I know, the definition of valence band is "the highest occupied band at absolute zero" However, I have...

Urgent! Absolute value help Homework Statement Heres an example :: |5x-3| = |x+1| we were given 3 cases for this type of problem in class they went something like this:: c.1 ) Use the 0 value for the right side and change all values in respect to (introduce - to all values) (x <...

Homework Statement |2x-8| + |12 - 3x | = 0 Homework Equations what do i do when it = 0 The Attempt at a Solution I tried solving it like all the others, but i know there is a unique thing to do when it = 0, i jus don't know what. So , here's what i did. 2|x-4| +...

Homework Statement How to solve x for these inequality? Homework Equations |x-2|/|x+3|> (x+2) / (x+1) The Attempt at a Solution (x - 2)/(x + 3) > (x + 2) / ( x+1) the left side holds the condition that is x >= 2 however, I wonder the next step. should I crossly multiply so...

kT where k is Boltzmann constant times the absolute temperature. what happen if the temperature is a variable?

Is it weird that at absolute zero in a metal, electrons at the fermi level still move around at the fermi velocity. Is the notion that everything stops at absolute zero incorrect? Thank you

Integral of 1/x = ln(x)... Problem has missing absolute value!? This is an ODE problem and solution, but what I'm not understanding here is calculus based: Why does the argument to the red-boxed ln() not in absolute value signs?? ( | | ) u = cos(t) so the numerator can be negative. I am just...

As a semi conductor approaches absolute zero there should be zero conductivity, the thermal energy that electrons acquire is or can be responsible for promoting electrons from the valence band to the conduction band to provide current flow in a semi conductor ( for t>0). My question is...

Homework Statement lim as x\rightarrow-1 = \frac{|x^{2}-1|}{x^{2}+x} Homework Equations N/a The Attempt at a Solution Tried to write this as a piecewise function, but I got lost.

Hi! Homework Statement I'm trying to work out this integral, without success: \int_{-a}^{a} (1-\left|x\right|/a) \frac{d^2}{dx^2}(1-\left|x\right|/a) 2. The attempt at a solution I tried solving this by parts, but I'm stuck: \int_{-a}^{a} (1-\left|x\right|/a)...

Homework Statement the question is in the diagram i have attached. basically i have to find absolute pressure Homework Equations P = pgh where P is Pressure and p is density The Attempt at a Solution 1st of all i need to convert 750mm into a pressure? somehow don't know exactly...

Can we consider gravitational force acting on a body considered as absolute force:-) if so pleas explain

The following matrix problem occurred to me. I figured out the answer and would like to pose the problem. It's easy but would be best for an undergrad math major. The question: Consider a square n by n matrix with entries 1, 2, ..., n squared. Find a way to arrange these entries so that the...

Hi, I’ve been teaching myself SR, currently reading Relativity for the Questioning Mind by Daniel F Styer. My math is not great, so I have been avoiding the heavy calculations for now. I will learn those too, but I wanted to understand the concepts first. For the most part I think I have...

Homework Statement solve the integral [abs(x+1)(3+abs(x))]/(x+1) between -3 and 1 Homework Equations The Attempt at a Solution when x<-1 then [abs(x+1)(3+abs(x))]/(x+1) = [-(x+1)(3-x)]/(x+1) = -(3-x) when -1<x<0 then [abs(x+1)(3+abs(x))]/(x+1) = (x+1)(3-x)/(x+1) = 3-x when x>0...

Homework Statement if f(x)=abs(x-2) and g(x)=abs(x), then solve the integral from -1 to 3 of abs(f(x)-g(x))dx Homework Equations The Attempt at a Solution resolved absolute values: when x<0, abs(x-2)-abs(x) = -x-2+x = 2 when 0<x<1, abs(x-2)-abs(x) = (-x+2)-x = 2-2x when 1<x<2...

I'm having trouble resolving the contradiction between theories of the Cosmic Microwave Background, and Special Relativity. Einstein denied the existence of any absolute standard of rest. As einstein-online.info paraphrases: "In the real world, there exists no such state of absolute rest...

Homework Statement Solve the equation | | 3x + 1 | - x | = 2 Homework Equations |x| = x if x \geq 0 |x| = -x if x < 0 The Attempt at a Solution To start, I have never dealt with such an equation before, and am partly 'iffy' with absolute values in general, but, up...

I know that water forms different kinds of crystals in different kind of temperatures but is there any temperature where water is solid but does not form crystals for example just above absolute zero degrees, what kind of crystals does it form?

Homework Statement y = ln | sin x | Homework Equations - The Attempt at a Solution No attempt at a solution, because it's more of a "which part of this is incorrect" question. y = ln | sin x | Would everyone agree that this is equivalent? y = ln \sqrt{(sin x^2)} Then...