9.6.2 Greatest hits from previous weeks

9.6.2.1 How to plot an ellipse?
9.6.2.2 Calculating the normalization constant for a wavefunction
9.6.2.3 Where can I find examples of good Mathematica programming practice?
9.6.2.4 How to make Jacobian automatically in Mathematica
9.6.2.5 How do I plot $x^2+y^2=1$ in 3D?
9.6.2.6 Cutting bagels into linked halves
9.6.2.7 How do I get the inverse of a homogeneous transformation matrix?
9.6.2.1 How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I'm new to Mathematica, and I'm finding it difficult to plot an ellipse. 
I tried using 
 
 Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}] 
 
 
but I'm getting ... 
[plotting]
 
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 Score of 19
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 Score of 33
9.6.2.2 Calculating the normalization constant for a wavefunction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=99248

How can I compute the normalization constant for a quantum mechanics wave-function, like $\Psi(x) = N \exp(-\lambda x^2/2)$ by using Mathematica? (The normalization constant is $N$). 
[physics]
 
asked by infiniteNOP https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35524 Score of 2
answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 Score of 5
9.6.2.3 Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ... 
[reference-request] [programming]
 
asked by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 590
answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 Score of 517
9.6.2.4 How to make Jacobian automatically in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790

If we have two vectors, $a$ and $b$, how can I make Jacobian matrix automatically in Mathematica? 
 
$$ a=\left( 
\begin{array}{c} 
x_1^3+2x_2^2 \\ 
3x_1^4+7x_2 
\end{array} 
\right);b=\left( 
\begin{array}{... 
[vector-calculus]
 
asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 Score of 41
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 Score of 58
9.6.2.5 How do I plot $x^2+y^2=1$ in 3D?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=10710

How would I plot $x^2+y^2=1$ in 3D (it would form a cylinder)? Since there is no $z$ in the equation, I can't solve for it and use  Plot3D . Or can I just put the ... 
[plotting]
 
asked by diracdeltafunk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2282 Score of 7
9.6.2.6 Cutting bagels into linked halves

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7545

I recently came across this video: Mathematically correct breakfast, which shows how a bagel can be neatly sliced into two identical linked halves. 
I'd like to try this with Mathematica. Here's a ... 
[graphics] [graphics3d]
 
asked by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 Score of 63
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 Score of 77
9.6.2.7 How do I get the inverse of a homogeneous transformation matrix?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=106257

I want to get the inverse of this homogeneous transformation matrix: 
 
 iab = { 
{1, 0, 0, 0}, 
{0, 0, -1, 0}, 
{0, 1, 0, 3}, 
{0, 0, 0, 1} 
} 
 
 
using the ... 
[matrix] [linear-algebra] [inverse] [geometric-transform] [rotation]
 
asked by andrestoga https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37677 Score of 6
answered by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 Score of 14