Positive Definition and 987 Threads

Hello everyone. I'm trying to set this problem up to prove by induction but having some issues. Suppose that for some Predicate P(k), you first prove that P(1) is true, and then you do the following. You prove that, for every positive even integer k, if P(i) is true for all odd integers i...

today is my first day here so if i violate any rule that apply in this forum please forgive me.. the question is Dr. Silverstein is driving a 1.95 * 10^3 kg car at 55.0Km/hr. He slams on the brakes and comes to rest in a distance of 17.0 m Assume that Dr. Silverstein has a mass of 75.0 kg...

hello everyone, I have a problem, if anyone can get me started. Thanks I have to show this equality knowing that a and b are positive and they do not euqal 0: (a^{2}+a^{\frac{4}{3}}b^{\frac{2}{3}})^{\frac{1}{2}} + (b^{2}+a^{\frac{2}{3}}b^{\frac{4}{3}})^{\frac{1}{2}}...

I'm trying to create an algorithm in MATLAB, but I have a problem. According to theory, if G is a positive definite matrix, then it's eigenvalues are positive real numbers. I'm using function EIG() to calculate the eigenvalues and eigenvectors of matrices, but I almost always take and negative...

http://i5.tinypic.com/4hionb9.jpg Please check my answers a) I know that e^x^3 > 0 and for all x ∈ [-1, 1], so we have ∫[-1 to 1] e^x^3 dx > 0. But how would you explain in words? b) For all x ∈ [0, 1] , 0 ≤ x^2 ≤ x , so e^0 ≤ e^x^2 ≤ e^x Therefore ∫[0 to 1] e^0 dx ≤ ∫[0 to 1]...

Do you consider ugliness a misery? Do you think is there any nice thing about being ugly?

I have a physics question that states: An amount of positive charge is distributed uniformly along the positive y-axis between y=o and y=a. A negative point charge -q lies on teh positive x=axis a distance r from the origin. Derive the x and y compontes of the force that the charge distribution...

lee smolin claims that SUSY/string theory can account for negative (anti-DS) and zero cosmological constant, but not a positive de-sitter constant, which is what has been observed. he also claims the kodama state in LQG has a good semiclassical limit that is GR, and incorporates a small...

How do you solve quadratic equations which have atleast one positive root?? The question was this: Find the value of 'm' for which the roots are such that at least one is positive. x2 -(m-3)x + m = 0 mR. Can someone help me get started? Here is my work: I checked the discriminant. for...

Cancellation or generation of positive energy by negative energy and vice versa is so often brought up by very serious physicists (e.g. A. Guth, A.V. Fillipenko) as the argumentation for the possibility of the generation of our universe out of “nothing”, that I hardly dare to question this. As...

I just can't justify this in my simple mind. I just always accepted it because I was told that it is equal to 1 throughout high school, and now in cegep. :confused:

An Hermitian matrix H is positive definite if all its eigenvalues are nonzero and positive. Assume that the matrices A,B are positve definite, and that the difference A-B is positve definite. Now, for which unitary matrices, U , is it true that the matrix A-UBU^{\dagger} is positve...

Aside from early diesel engines, does anyone know of brayton-cycle engine that uses a positive displacement compressor rather than an aerodynamic one?

What materials for positive pole, negative pole and what acid when put together create a perfect battery? (I'm not talking about everyday purpose for a batery (so never-mind how bio-hazardous a material is), but a theoretical (greatest voltage, greatest current possible, yet stable enough (so...

Hello everbody I have functions of two variables and I need to determine if they are positive or negative. I am just wondering if anyone can tell me what the best way to do that is? Thanks a lot in advance

An object of mass 2 kg is repelled from the origin by a force in the +x-direction whose magnitude varies with x according to F=(7Nxm^2)x^-2. How much work is done by this force when the object moves from x=2 to x=3? (Be sure to say whether this work is positive or negative.) I have no idea...

how do you prove the set of vectors "all ordered quadruples of positive real numbers" make a vector space?

A region in space contains a total positive charge Q that is distributed spherically such that the volume charge density rho (r) is given by: rho (r)=3 * alpha * r /(2R) for r ≤ R / 2 rho (r)= alpha * [1-(r/R)^(2) ] for (R/2) ≤ r ≤ R rho (r)=0 for r ≥ R Here alpha is a positive...

I need some help in finding a way to solve the following problems.: - Two equal positive charges q are on the y axis, one at y= +a and the other at y= -a. a) Show that the electric field on the x-axis is along the x-axis with Ex= 2kqx(x2 + a2)-3/2. b) Show that near the origin, when...

I have three math problems that I am unsure of how to do. could someone please help thanks. \sqrt[3]{-8x^3y^3z^3} ({4xy^-1}/{16xy^2}) \sqrt{98}+\sqrt{2}

I have been asked to explain without evaluating the integrals why 1) the integral of x cos x from 0 to pi/2 is positive and the integral of x cos x from pi/2 to pi is negative. And also would I expect x cos x from 0 to pi to be positive, zero or negative? And why ? 2) to find the...

4 to the power of 27 + 4 to the power of 1000 + 4 to the power of x. x is the maximum positive integer and it adds up to a perfect square?

Question goes as follows: "In an ionised gas there are positive ions and electrones moving around in collision with molecules of the gas. Calculate the ratio of the mean free path of the electrons in the gas to the mean free path of the positive ions in the gas." As far as I can see I...

Can't figure it out Prove that if n is an odd positive integer, then one of the numbers n+5 or n+7 is divisible by 4 My thoughts I don't know if this is right- Multiply n+5 and n+7, because if one of them is a multiple by 4 then shouldn't their product be divisible 4

Hello! I need a help with one question: Discuss weather any work is being done by each of the following agents, and if so, wether the work is positive of negative. a) a chiken scratching the ground (what I think is that work is performed as W=F∆x, and if the chicken moves her leg back and...

A positive point charge q is placed at x=a and a negative point charge -q is placed at x=-a. a: find the magnitude of the electric field and the direction at x= 0. b: derive an expression for the electric field at points on the x-axis. use results to graph the x-component of the electric field...

when does friction in a car becomes positive? in a dry surface and i na wet surface and on ice.

I was working with Fourier series and I found the following recursive formula for the zeta function: \frac{p \\ \pi^{2p}}{2p+1} + \sum_{k=1}^{p} \frac{(2p)! (-1)^k \pi^{2(p-k)}}{(2(p-k)+1)!} \zeta(2k) = 0 where [itex]\zeta(k)[/tex] is the Riemann zeta function and p is a positive integer. I...

So let's be positive then... What are some of the great qualities in likely 2008 presidential candidates? No smears please. I'll start the ball rolling. John Edwards is working with the Poverty Center in North Carolina. The aim of this center is to "combat poverty in a way that honors...

im always confued about negative and positive signs, soemone give em a easy way to remember is whatever is on the left side of the x-axis egative, and above positive always? also when is friction negative, if the mass if moving up a ramp, is friction always negative, and if its moving down...

Hey, I have this task that may seem simple, but really isn't: When a box moves across a surface the force of friction does a negative work. Can a friction force ever do a positive work? Possibility 1: Yes, because else what is it then that moves your car forward when you accelerates...

Hey folks. I thought i might check my answers and confirm if theyre right or not. the following have to be simplified and expressed with positive indices. Below are the indices; 1. (√a^2b^3)^6 2. (x^a y^-b)^3 (x^3 y^2)^-a 3. (27x^3/8a^-3)^-2/3 4. {4√(x^-2/3 y^1/2)^3)}^-2/3...

Four charges are placed on the corners of a rectangle. What is the resultant force on the positive charge (a = 1.3 m, b = 0.8 m, q = 1.8 × 10-9C)? HELP: Use Coulomb's law and superposition. HELP: Superposition tells us that we can find the force on the positive charge by looking at the...

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Let (x(n)) and (y(n)) be sequences of positive numbers such that lim(x(n)/y(n)) = 0. If lim(x(n)) = +∞, then lim(y(n)) = +∞ If (y(n)) is bounded, then lim(x(n)) = 0 To me this is self-evident. But HOW can it be proved?

You probably think that adding one to zero gives you one. But, let us examine this process a little closer. Imagine being at absolute negative infinity. I know, you are probably thinking that infinity goes on forever, which indeed it does, and therefore we cannot comprehend the point at...

The U.S. seems caught in a love-hate relationship with the rest of the world. What would you say is our most admirable quality, and what the most detestable?

Hi, I have been reading the paper "Quantum Gravity with a Positive Cosmological Constant" by Lee Smolin (http://arxiv.org/abs/hep-th/0209079), and am having some trouble making the constants in Part I, Sections 2, 3, and 4 match with what I would calculate them to be when I try to go through...

I don't know why there is such hatred against the approval of the dot-xxx domain. Personally I think that it is a great idea because the whole idea of domains is to categorize websites, right? Getting all adult content on this domain is another challenge but it's a good call.

"A positive operator A is defined to be an operator such that for any vector |v>=!0, <v|A|v> is real, non-negative number." Can somebody tell me how can I check if a matrice (for example 4x4) is positive or not? Thanks in advance

I have two quick questions. The first is, if a ball is thrown from a bridge 25 meter above the ground at 49m/s, is the acceleration negative? I thought since it was thrown up, it would be positive, but the book has a similar problem, a ball is thrown upward at a speed of 48ft/s from a cliff...

Hi everyone, This is my first post here :smile: Anyway I have problems solving this question wonder anyone could help give me some clues as to how to go about it. Here goes: The positive integers are bracketed as follows, (1), (2,3), (4,5,6,7), (8,9,10,11,12,13,14,15), ...

I am asked to list the positive rational numbers in one list so that the pattern of the order is clear and so that all the positive rational numbers would eventually appear on the list. Then I have to explain the pattern and why every positive rational number will eventually be on the list...

Suppose there is a positively charged wire inside a negatively charged cylinder. What would be the net external electric field? Would I first need to combine the charges, or can I just combine the separate fields?

fi have no idea what to do and i tried posting it on another forum and nobody replied so please help me! thank you so much! find a positive integer n so that 40n is a fifth power (of an integer) 500n is a sixth power, and 200n is a seventh power, or explain why it is impossible to do so...

For a positive natural number n, we use |n|= \log_{2}n as the measure of the size of n (which is the number of bits in n's binary representation). however, in most cases the size of n can be written as log n without giving an explicit base (the omitting case is the natural base e). Show...

Hi. I am doing an investigation on the effects of different antibiotics on Gram positive and Gram negative bacteria. 1) Can you say that antibiotics and bacteria form a chaotic system? Can a very small change in concentration of antiboitics, or a small variation in pH, change the diameter of...

Do all positive slopes taken from points (x1, y1) and (x2, y2) satisfy the following logic, x1 < x2 and y1 < y2?

this is quite a classic problem i think but I am having difficulty finishing it off. If we have two stamps of positive values a and b, (greater than 1), what values can be expressed as a linear combination of these 2 stamps. If the stamps have a highest common factor greater than 1, then there...