general
'H' symbol as a power of matrix
Here is capture of problem That is what I saw while I was studying maximum ratio combining (MRC) in communication. It is probably very simple and stupid t...
Apr 19, 2026
Archive: General
general
Folland, Real Analysis problem 1.18
This comes from an exercise from Real Analysis by Folland. Let $\mathcal{A}\subset P(X)$ be an algebra, $\mathcal{A}_\sigma$ the collection of countable u...
Apr 19, 2026
general
Perimeter or Calculus Word problem
A rectangular plot of farmland will be bounded on one side by a river and on the other three sides by a single strand of electric fence. With 1400m of wir...
Apr 19, 2026
general
prove that derivative exists or doesn't exist
I am solving couple of problems to an upcoming test and I have a question regarding the understanding of the derivative. consider the following function: ...
Apr 19, 2026
general
How to change the order of summation?
I have stumbled upon, multiple times, on cases where I need to change the order of summation (usally of finite sums). One problem I saw was simple $$ \sum...
Apr 19, 2026
general
$\epsilon$/3 - Proof for converging sequence of functions
I tried to prove the following statement and would like to ask if it's okay like that. $\underline{Statement}$: Let [B,$||.||_B$] be a complete norme...
Apr 19, 2026
general
Calculate transitive closure of a relation
I am trying to understand how to calculate the transitive closure of a set and I have read several times the definition of the transitive closure but I st...
Apr 19, 2026
![Wolfram alpha plot of a piecewise function with 2 domains. [closed]](https://news.conceivablytech.com/uploads/wolfram-alpha-plot-of-a-piecewise-function-with-2-domains-closed_720.jpg)
general
Wolfram alpha plot of a piecewise function with 2 domains. [closed]
So, Wolfram Alpha is capable of plotting two functions in one figure. But I am trying to express a piecewise function that has a different form on two (to...
Apr 19, 2026
general
Why group cohomology and not group homology?
In algebraic topology, one studies the homology and cohomology of spaces. However, when we study group homology/cohomology, we almost exclusively talk abo...
Apr 19, 2026
general
Calculating $17^{14}\mod{71}$ using Fermat's little theorem
Calculate $17^{14} \pmod{71}$ By Fermat's little theorem: $17^{70} \equiv 1 \pmod{71}$ $17^{14} \equiv 17^{(70\cdot\frac{14}{70})}\pmod{71}$ And then...
Apr 19, 2026
