1. B

    Understanding a specific Chebyshev integral

    I have a situation where I'm trying to understand the physics of a cooling tower. Part of the solution for the model I'm working with involves an integral: C = \int_{T_{low}}^{T_{high}} \frac{1}{\left(h' - h_a\right)} dT where h' is a slowly varying, monotonically increasing function with...
  2. S

    Could someone please explain how a specific part of the expression for the Riemann su

    I'm really sorry if this post is not appropriate for this forum. My math level is quite low and it might have been because of that I could not understand this concept. So, the problem that I have is that I don't understand how a part of this expression is generated: 1. $$S =\sum_{i=1}^n 2...
  3. D

    How to find functions & inputs whose output is a specific number

    I'm interested in the following problem: given a random number n (n can be gigantic), how do we find a pair function+input(s) whose output is n such that the input(s) are relatively small in size? This problems arises in data compression; consider the bits that make up a file (or a substring...
  4. idontknow

    Specific limit case

    Let L be the limit of a function . If L\rightarrow 2L\; , How to evaluate the limit ? When it is 0 and when infinity?
  5. E

    Limit of specific functions

  6. K

    Isolating a specific expressing for an equality equation

    I have this equation with the equality: $$b(\tau )\left\{ {\sigma {e^{ - qr - {1 \over 2}\mu _ + ^2( \bullet )}} + q\sqrt {2\pi \tau } - q\sqrt \tau \int\limits_0^\tau {{e^{ - qu - {1 \over 2}\mu _ + ^2( \bullet )}}} \left( {{{{\mu _ - }( \bullet )} \over u}} \right)du} \right\} = K\left\{...
  7. J

    Developing equation to satisfy specific parameters (potentially partial derivatives?)

    I'd like to start out by stating that I am an engineer, but would not consider myself a math expert. Which is why I am posting here; so I can pick the brains of those that eat and breathe this stuff (and are likely much smarter than me) :) I have a unique problem that I am trying to solve by...
  8. M

    How to solve for monthly amount to get $200k payout after specific payment term?

    I am trying to find a formula to solve for the monthly starting amount below: Monthly Starting Amount = ? Payment Term = 10 years, 5 months (125 monthly payments) Indexation = 2% per year, compounded Total Future Payout = \$200,000.00 That is, what is the required monthly starting amount you...
  9. S

    Finding frequency of a specific mechanical oscillator -- horizontal rod on pivot

    There is a cyllinder with radius 0.5 m fixed on the wall. We put a 6 metres long thin rod with mass 0.3 kg on it, which does not slip. I would like to calculate the oscillating time. It is a part of a clock, so the oscillating time is probably 1 or 2 seconds, but I got around 5 seconds. Please...
  10. A

    Probability to be born on a specific day

    Problem: https://en.wikipedia.org/wiki/Birthday_attack I don't understand the two formulas (for getting 7.9% and for 70%). Could someone explain me, please?
  11. M

    Can anyone explain the specific steps involved

    I know the problem itself involves calculus, but I'm confused about the algebra that is involved here. Can someone specifically explain (step by step) how they got from step 2 to step 3? Thank you in advance.
  12. M

    Specific multiples of p (p odd prime)

    Hi, Do we know how to compute for some given n the number of multiples of an odd prime number p such that they are not divisible by a prime < p ? n=50 p=5 the multiples of 5 from 5 to 50 are 10, 15, 20, 25, 30, 35, 40, 45, 50 but only 25,35 are not divisible by 2 and 3 (2 and 3 are <5) If we...
  13. S

    Specific Algebra Problem

    Hey forum, I have a problem with a specific math problem - I found the formulars on a wiki, link is here (Armour/math - Official Path of Exile Wiki) however I don't understand how to calculate what is called D_net since I don't have D_raw or DR which just loops thereby giving me two unknown...
  14. A

    looking for specific book

    Nyman, Bertil (1950), On the One-Dimensional Translation Group and Semi-Group in Certain Function Spaces, PhD Thesis, University of Uppsala: University of Uppsala, MR 0036444. prefer to buy a copy just can find it
  15. V

    Generate Time Series with specific ACF and multiple LAG

    Hello Everyone, I will try to explain what am I doing here and I hope someone will understand. ACF - autocorrelation function I'm doing a research about non-parametric methods utility. How they fit and are useful in a different environment. I'm generating time series with different sizes...
  16. A

    Rewrite an expression in a specific form

    I have an expression that looks as follows: n + (a*x+b)^c. Where 'a', 'b', 'n', and 'c' are constant numbers. The ranges of the parameters are: n = [0,0.2] a = [0.5,1.5] b = [-0.5,0.5] c = [0.5,1.5] x = [0,0.6] I would like rewrite this expression such that it will look as follows...
  17. shunya

    Find a specific number

    Find the smallest number n with the following property: If n is divided by 3, the quotient is the number obtained by moving the last digit (ones digit) of n to become the first. All of the remaining digits are shifted one to the right. Thanks
  18. L

    Help with writing a specific polynomial function

    Ok so I was looking through my book and I saw the problem. Write a polynomial function with zeros -2 and 1+i, that also fits f(-2)=4. The zeros should be -2 1+i and because 1+i is a complex number, another zero would be 1+i. How could f(-2)=4 when -2 is a zero??? Can anybody help me out with this?
  19. G

    Specific solutions in the null space of a complex matrix

    Hello, I'm dealing here with the following problem: I have a complex matrix F, having size N \times M, with N<<M. I can easily compute a basis of the null space of F, i.e. the space of vectors x such that Fx=0_v, where 0_v denotes the N \times 1 column vector of all zeros. However, I'm...
  20. E

    Looking for an specific summation property

    Hello folks, I'm looking for a summation property like below: If the property has more summations involved then better. The key point is that the sum of pi values over the summation iteration be equal to 1. Thanks in advance! :rolleyes: