9.1.1 Top new questions this week

9.1.1.1 Automating interesting ways to write 2023
9.1.1.2 How can I create a shortcut to convert "normal Symbol" to Formal Symbol?
9.1.1.3 How to Create Kaptiza's Pendulum?
9.1.1.4 Function that imitates Thread
9.1.1.5 Inertia tensors for non-typical rigid bodies
9.1.1.6 What is a good way to compute successive primorials with Mathematica?
9.1.1.7 PDE involving derivative at boundary, with a boundary condition at infinity
9.1.1.1 Automating interesting ways to write 2023

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278023

Inspired by Interesting ways to write 2023, I was wondering if there are ways to automate the search for results using MMA. 
I tried 
... 
[functions] [function-construction] [code-request] [factorization]
 
asked by Moo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36141 Score of 14
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 Score of 13
9.1.1.2 How can I create a shortcut to convert "normal Symbol" to Formal Symbol?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278072

I'd like to create a shortcut to convert a selected symbol, say  \[Delta] , into its rough equivalent formal symbol (i.e., ... 
[keyboard] [built-in-symbols]
 
asked by Craig Carter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12461 Score of 11
answered by E. Chan-López https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53427 Score of 6
9.1.1.3 How to Create Kaptiza's Pendulum?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278142

Hi, I have never worked on a project of this kind before. I am having difficulty using Kapitza's Pendulum (inverted pendulum with moving vertical base). 
It is hard for me to make the model equations, ... 
[differential-equations] [modeling] [education]
 
asked by Tetrasreal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89698 Score of 10
answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 Score of 12
9.1.1.4 Function that imitates Thread

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278075

I am fairly new to mathematica. I was given two lists i.e {x1, x2, x3, x4} and {a,b,c,d} and I had to produce the following: 
 {x1->a,x2->b,x3->c,x4->d} 
 
... 
[list-manipulation]
 
asked by imbAF https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89668 Score of 8
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 Score of 7
9.1.1.5 Inertia tensors for non-typical rigid bodies

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=277997

Calculate inertia tensors 
This topic inspired me to experiment with calculating tensors of more complex shapes of rigid bodies (I did not find them in the Mathematica database). 
For simple shapes of ... 
[calculus-and-analysis] [regions] [physics] [solidmechanics]
 
asked by dtn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67019 Score of 8
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 Score of 7
9.1.1.6 What is a good way to compute successive primorials with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278112

Recall that the primorial of a positive integer $n$ is the product of the prime numbers smaller than $n$. One can define a primorial function in Mathematica quite easily: 
... 
[performance-tuning] [prime-numbers]
 
asked by Klangen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49819 Score of 7
answered by rhermans https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10397 Score of 11
9.1.1.7 PDE involving derivative at boundary, with a boundary condition at infinity

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=278011

I am trying to find the function $T(z,t)$ which solves this differential equation: 
$$\frac{\partial T}{\partial t}=\frac{\partial^2 T}{\partial z^2}+St\left[ \exp\left [ -\frac{\left( x_f-Ut\right )^2}... 
[differential-equations] [calculus-and-analysis] [boundary-condition-at-infinity]
 
asked by umby https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58367 Score of 7
answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 Score of 5