8.36.1 Top new questions this week

8.36.1.1 Track chord movement
8.36.1.2 Why does ReplaceAll not work here?
8.36.1.3 Italic style in the label
8.36.1.4 How to create all possible graphs that connect all vertices?
8.36.1.5 Still bug in Integrate. 2
8.36.1.6 FEM breaks because of Abs(f'(x))
8.36.1.7 How to efficiently find all element combination including a certain element in the list
8.36.1.1 Track chord movement

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275699

The point $P$ on the circle and the point $F$ inside the circle, perpendicular bisector of line $PF$ intersects the circle at two points $A, B$, the envelope of $AB$ is an ellipse. 
I use the following ... 
[graphics] [manipulate] [geometry] [animation]
 
asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 Score of 6
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 Score of 7
8.36.1.2 Why does ReplaceAll not work here?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275837

Why does this not change the names of the vertices? 
... 
[functions] [graphs-and-networks] [replacement]
 
asked by hana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82512 Score of 5
answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 Score of 7
8.36.1.3 Italic style in the label

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275775

For the FrameLabel, I have: 
 Style["\[NumberSign] Humans per city", FontFamily -> "Latin Modern Math"] 
 
How can I make only "Humans" ... 
[labeling]
 
asked by Marteen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=88712 Score of 5
answered by lericr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=84894 Score of 4
8.36.1.4 How to create all possible graphs that connect all vertices?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275779

How can I generate all labelled connected simple graphs on  n  vertices? 
In the image below, I drew examples with number of vertices ... 
[functions] [function-construction] [graphs-and-networks]
 
asked by hana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82512 Score of 5
answered by user293787 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=85954 Score of 6
8.36.1.5 Still bug in Integrate. 2

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275760

Let us consider in version 13.1 on Windows 10 
 a = Integrate[(-t^2 + 1)^s/((2^(-s) + t^s)*(t^2 + 1)) /. s -> 3/2, {t, 0, 1}] 
 
 
... 
[calculus-and-analysis] [bugs]
 
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 Score of 5
answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 Score of 5
8.36.1.6 FEM breaks because of Abs(f'(x))

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275766

I am trying to solve a 1d differential equation in Mathematica using the finite element method. I have successfully implemented the problem in a commercial software called COMSOL, but I like to use ... 
[differential-equations] [finite-element-method] [stiffness]
 
asked by Nils https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=88640 Score of 4
8.36.1.7 How to efficiently find all element combination including a certain element in the list

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=275804

I have the following list : 
 alist={{5, 6, 7}, {7, 6, 8}, {5, 7, 25}, {7, 8, 26}, {7, 26, 25}, {5, 4, 6}, {4, 12, 6}, {6, 12, 13}, {6, 13, 8}} 
 
I want to find all ... 
[list-manipulation] [permutation]
 
asked by mmmm https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=88659 Score of 4