10.37.3 Can you answer these questions?

10.37.3.1 How to make the effect of writing papers in Mathematica reach the same level as LaTeX?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=308365

Specific Problem 1: How to achieve the same effect in Mathematica as adding a colored box around a line or paragraph of text in LaTeX (as shown in the figure below)? 
This is also an open-ended ... 
[latex]
 

asked by user103271 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=103271 Score of 1

10.37.3.2 Can Mathematica differentiate summation notation with respect to an indexed variable?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=308409

My question is whether Mathematica can represent an expression such as: 
$$y_i = \sum_{j=1}^N a_{ij} x_j$$ 
symbolically as a sum over indefinite bounds (unknown N), and differentiate it with respect to ... 
[calculus-and-analysis] [summation]
 

asked by causative https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=103584 Score of 1

10.37.3.3 NDSolve: Prescribe a linear constraint on a boundary

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=308283

This is a representative volume element problem on a unit square. 
I would like to apply the following linear constraint on a boundary: 
$u(x,1)=u(x,0)+0.3$ 
How can do this? There seems to be no way. ... 
[differential-equations] [finite-element-method] [boundary-conditions] [constraint]
 

asked by Rainer Glüge https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18671 Score of 1