10.42.1 Top new questions this week

10.42.1.1 Evaluation leaks in calling N[] on held expressions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309490

Calling  N[]  on a held expression converts the numbers it contains to approximate numbers (unless an argument is protect by ... 
[evaluation] [hold] [numerical-value]
 

asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 Score of 13

10.42.1.2 Why is truncation faster than direct polynomial expansion?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309523

Try the following codes 
 n = 500; 
precision = MachinePrecision; 
l = RandomReal[{}, n, WorkingPrecision -> precision]; 
poly = Times @@ (x - l); 
 
Now try to expand ... 
[polynomials] [series-expansion]
 

asked by lapcal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=85338 Score of 10

answered by Daniel Lichtblau https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51 Score of 11

10.42.1.3 NIntegrate cannot give high precision result for a well-behaved integral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309414

I want to obtain value of following integral to a high precision (say 30 digits), 
 NIntegrate[DawsonF[Sqrt[t]]^2/t, {t, 0, Infinity}] 
 
Graph of integrand looks like ... 
[calculus-and-analysis] [numerical-integration] [special-functions]
 

asked by pisco https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54457 Score of 8

answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 Score of 9

10.42.1.4 Limit the difference between two sliders in Manipulate

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309423

Consider this Manipulate 
 Manipulate[{x, y}, {{x, 0}, -2, 2}, {{y, 0}, -2, 2}] 
 
 
Each of the sliders can move freely and independently. But, I want to impose a ... 
[manipulate] [dynamic]
 

asked by Naraghazi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=104474 Score of 7

answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 Score of 10

10.42.1.5 Mathematica will not compute this integral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309476

I am trying to compute the following integral, but regardless of FullSimplify or Assumptions, Mathematica seems unable to compute it. I have already tried computing the indefinite version and evaluate ... 
[calculus-and-analysis]
 

asked by Oti https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99752 Score of 5

answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 Score of 11

10.42.1.6 SelectFirst and Hold

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309459

Say I have a list of  Hold  elements. I use  Hold  because the operations are quite expensive (they are integrals). 
I want to return ... 
[list-manipulation] [functions]
 

asked by Paul R https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=96326 Score of 5

answered by Edmund https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19542 Score of 4

10.42.1.7 Difficult Fourier transform

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309391

I need to compute the Fourier transform of a simple rational function times hyperbolic secant distribution 
... 
[calculus-and-analysis] [fourier-analysis]
 

asked by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 Score of 5

answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 Score of 6