Absolute Definition and 1000 Threads

  1. E

    Is there an absolute motionless?

    So I do not have a clue whether this question has any merit or not. (which is why I came here) I have heard that masses create ripples in space-time (gravity waves) as they move. I have drawn a couple of logical conclusions that I would appreciate if you guys would verify or discredit...
  2. T

    Writing an absolute value function as a piecewise function

    Homework Statement Write f(x) = |x2-x-12| as a piecewise function. Homework Equations The Attempt at a Solution -x2+x+12 where x>1/2 x2-x-12 where x\geq0 According to the answer book the answers are -x2+x+12 where -3<x<4 x2-x-12 where x\geq4 2x2-5x-3, x\leq1/2 I am...
  3. phosgene

    Absolute pressure of air inside a meat baster

    Homework Statement A meat baster consists of a flexible bulb attached to a plastic tube as shown in the diagram. When the open end of the tube is immersed in the basting sauce and the bulb is squeezed then released, sauce rises in the tube so that it can be squirted over the meat. Suppose...
  4. M

    Proof of an expression involving absolute value

    Homework Statement Prove: for any real number x, -|x|\leqx\leq|x|. Homework Equations Only the definition of absolute value is allowed. The Attempt at a Solution Don't even know where to start
  5. M

    Proof of an expression involving absolute value

    Homework Statement Prove: |ab|=|a||b|. (Hint: Consider the cases separately for various signs of a and b.) Homework Equations I think it asks me to prove it only from the definition of absolute value (if it is possible). The Attempt at a Solution |ab|= \frac{(ab), if (ab)\geq0}{-(ab), if...
  6. D

    Absolute Proof Einstein Was Wrong (not really)

    I have developed a theory that shows that the more massive an object, the faster time seems to move, thus proving that time dilation is wrong. You see, as I get older, I've noticed I've been gaining more weight, but it seems I have less time to do the stuff I want now rather than more time...
  7. M

    Absolute and apparent magnitude

    is that both of absolute and apparent magnitude counts only visible light? since i found some books said absolute magnitude counts luminosity instead of intensity, where luminosity includes also the non-visible frequencies. thank you!
  8. A

    Derivative of cubic absolute value function

    Homework Statement f(x) = |x+2|^3 -1 The Attempt at a Solution - So, I know the formula is: d|x| / dx = x / |x| - My guess would be: (x+2)^3 / |x + 2|^3 ? I'm trying to find Increase and Decrease intervals for the graph..
  9. M

    Opposite of Absolute Zero? Absolute Hot?

    I've heard of something called Absolute Hot...the opposite of Absolute Zero (Absolute Cold). What happens at Absolute Hot?
  10. D

    If a absolute point would exist, still relativity theory would be valid

    Consider an absolute point somewhere in one of the universes and consider our light signal with constant speed C which expresses time and distance (same in fact). If you don't know this point, the relativity theory would be exactly the same. If you know this point, you could say...
  11. K

    Double integral absolute value.

    Homework Statement I just need to know if what i did is correct. The question is as follows: http://imgur.com/1RL7e Homework Equations The Attempt at a Solution What I did is as follows: I split this integral into two parts and solved. [integral from 0 to 1...
  12. D

    Conditional and absolute convergence (of series)

    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...
  13. P

    Analysis: Absolute convergence, rearranging terms, power series question

    Homework Statement I can't figure out what my professor means in the last two lines: I'm trying to prove why the product of two analytic functions is analytic, and I think that I am going to need to use a similar construction. The Attempt at a Solution So far to prove the product...
  14. P

    How to integrate modulus function ( absolute value) within the specified limits

    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...
  15. C

    Binary stars apparent and absolute magnitudes

    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)...
  16. T

    Derivatives of ln including Absolute Value

    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...
  17. P

    Absolute pressure with container

    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...
  18. P

    Calculating Absolute Gravity Using Relative Measurements for Scientists

    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...
  19. M

    Finding Absolute Zero Experimentally: Investigating a Capillary Tube

    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...
  20. N

    Local Minimum of y=x(e^1/x): Why Not (1,e)?

    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
  21. P

    Is there really an absolute reference frame?

    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...
  22. T

    Alternating Series Tests: Understanding Conditional & Absolute Convergence

    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...
  23. K

    System of equations incl. complex and absolute values

    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...
  24. M

    Does the Absolute Value of this Series Converge? A Scientist's Dilemma

    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...
  25. F

    What is the Absolute Value of b(t)?

    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...
  26. G

    Complex inequality with absolute values

    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...
  27. S

    Did I explain this right? Basic absolute value functions

    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...
  28. N

    Absolute Space and Moving Co-ordinates.

    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...
  29. N

    Do Particles Stop Radiating at Absolute Zero?

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

    Understanding Energy of a Signal: Integral & Absolute Value Sign

    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...
  31. D

    Absolute potential from sphere.

    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...
  32. S

    Does the Limit Exist for Absolute Value as x Approaches -8?

    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...
  33. M

    Intergrating a derivative of absolute value in exponential

    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??
  34. W

    Force through absolute Pressure

    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?
  35. F

    Absolute valuing both sides probably a big no-no in Math

    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 =...
  36. khurram usman

    Understanding the Relationship between Square Roots and Absolute Values

    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...
  37. A

    Absolute Uncertainty - Enough Information?

    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...
  38. P

    Absolute values resulting in diff-eqs

    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...
  39. Y

    Can cosmologist mathematicians compute all the way to absolute nothingness?

    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...
  40. N

    Why Does the Negative Sign Become Positive in Absolute Value Equations?

    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...
  41. A

    Why is the term 'norm' used instead of 'absolute value' in vector spaces?

    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}||?
  42. P

    Absolute value equations with extraneous solutions

    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...
  43. W

    Is the conduction band of metals empty at absolute zero?

    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...
  44. N

    Solving Absolute Value Equations: Understanding Restrictions and Changing Values

    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 <...
  45. N

    Absolute Value Equations: Solving |2x-8| + |12-3x| = 0

    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| +...
  46. W

    Inequalities involving division of two absolute values

    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...
  47. P

    KT where k is Boltzmann constant times the absolute temperature.what

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

    Do particles in a system at absolute zero still have kinetic energy?

    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
  49. Jonnyb42

    Integral of 1/x = ln(x) Problem has missing absolute value?

    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...
  50. A

    Conductivity of a metal approaching absolute zero

    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...
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