1. W

    absolutely convergent series

    Hello. I want to show that, for an absolutely convergent series \sum_{n=1}^{\infty}a_n, we have \left|\sum_{n=1}^{\infty}a_n\right|\leq\sum_{n=1}^{\infty}|a_n|. Let M be an positive integer. I begin with the triangle inequality \left|\sum_{n=1}^{M}a_n\right|\leq\sum_{n=1}^{M}|a_n| and taking...
  2. B

    I can't calculate a simple infinity integra!!!

    x(t) = \begin{cases} 1 \quad ,0 \leq t \leq 1 \\ 0 \quad ,else \end{cases} The book says to calculate the integral below which must be 1, but I find infinity. \lim_{T \to \infty} \int_{-T}^{T} |x(t)|^2 \cdot dt = 1 My calculation \lim_{T \to \infty} \int_{-T}^{T} |x(t)2|^2 \cdot dt =...
  3. S

    Limit tending to infinity

    I am unable to find out the limit of this entire sum with n tending to infinity. I know the concept of definite integral. However, I am unable to apply that. Please help me out.:(
  4. S

    infinity of irrational numbers between i. numbers

    How I prove that between irrational number there is infinity of irrational numbers?
  5. D


    Set theory uses the ‘axiom of infinity’ which is equivalent to ‘actual infinity exists’. I believe this axiom is wrong - Actual Infinity cannot exist: Numerically: - There is no natural number with the property that repeatedly subtracting one from it never reaches zero - Hence...
  6. fedeblaze

    GeoGebra and Limits at Infinity (Commands)

    Hi guys! Would you help me with all the commands on GeoGebra that you know to graph Limits at Infinity? I'd really appreciate it. Thank you. :wink:
  7. Z

    Cantor's Diagonal Argument and Infinity

    If infinity means endless, you can never get to the end of CDA.
  8. C

    concerning infinity as the limit involving square roots in the function

    Dear MyMathForum Community: In using some notation from the Pascal programming language, As x --> infinity, sqrt(x + 1) / sqrt(4x - 1) = 1/2. Why is this true?:)
  9. C

    Concerning infinity as a limit

    Dear MyMathForum Community: This is the problem: as x --> infinity, (2x+3)/(5x+7) = 2/5. Why is this so? Thank you.:)
  10. M

    Showing a sequence does not diverge to infinity using definition

    Is there a definition for a sequence that does not diverge to infinity? Can I negate the definition of divergence to infinity of sequence, like I can do with convergence? What I mean is, convergent sequence definition is: "A sequence (an) is said to converge to L provided that for each ϵ>0...
  11. J

    How to solve this limit?

    Because this is irrational function, I know there is no limit at this point (-1/y) because limit from the left and from the right are not equal, but how to calculate the limit from the left or from the right for this particular function? I know they are +/- infinity, but I do not know how to...
  12. J

    How to calculate this limit?

    Hi! I know that the value of this limit is 1, but I do not know how to calculate it:
  13. L

    Epsilon Delta for infinity

    Hello Guys, I need someone to explain me the answer. Especially, how did we get 1.526 using arctan 22.36? I used the arctan function of the calculator and typed arctan((22.36) and I did not get the same numbers. Please explain to me how 1.526 and 0.0447 are obtained. I really appreciate...
  14. Q

    Infinity proof?

    Another proof in the making. There may be some mistakes in this one, feel free to let me know what to do to ensure it's correct.
  15. K

    Infinity Boundlessness

    Set containment is the general basis for infinity boundlessness. Numbers describe the thing, a set of numbers describes a set of things. To describe boundlessness, the number takes on the property of the boundlessness itself. To describe boundlessness set property one must understand the two...
  16. M


    Infinity is always more than 0 and less than 1!
  17. J

    Is the set [0,infinity) bounded?

    This question sounds silly, but I was just wondering since we are saying that the elements of the set are only for numbers greater than 0.
  18. R

    New blog: Infinity Plus One

    So, I've started a new blog, Infinity Plus One, discussing more advanced math topics, but aimed at a lay audience. I thought this forum looked like a place where people interested in this kind of resource (or who know those who would be) congregate. So, here are links for my first two posts. I...
  19. Devin Baugher

    1/2 Infinity?

    A Finite Amount of an Infinite Number I have had infinity on my mind lots lately, and one of the things that most intrigues me is something that I feel that I have come up with but do not know if it was discovered prior to this. Here is what I propose: there can be an infinite amount of...
  20. P

    Limit involving derivative of zeta function

    Hello. I would like to know what is the value of the derivative of 1/ (zeta(x)) as x tends to 1: \displaystyle \lim_{x \to 1} \frac{d\frac{1}{\zeta(x)}}{dx} As you get an indetermination of the type 0\infty , what I have tried so far is to apply L'Hôpital's rule, but with no success. Thank...