7.1.2 Greatest hits from previous weeks

7.1.2.1 What do the X and Y axis stand for in the Fourier transform domain?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139

In Wolfram Mathematica the function  Fourier  has the following declaration 
 
 Fourier[list] 
 
 
And after a list is given to the ... 
[numerics] [fourier-analysis] [faq]
 

asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes

answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes

7.1.2.2 How can I plot the direction field for a differential equation?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841

I'd like to plot the graph of the direction field for a differential equation, to get a feel for it.  I'm a novice, right now, when it comes to plotting in Mathematica, so I'm hoping that someone can ... 
[plotting] [differential-equations]
 

asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 31 votes

answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 25 votes

7.1.2.3 Is Mathematica worth it for me?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=100072

I'm 13 years old and in 7th grade. I'm currently in Algebra 1, and I have fallen in love with both math and programming. 
 
When I came upon Mathematica, it was awesome. My two favorite things fused ... 
[programming] [education]
 

asked by Nico A https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35769 81 votes

answered by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 55 votes

7.1.2.4 How to ask Mathematica to imitate Andy Warhol's pop-art painting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132

I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe's portrait so that it looks like Warhol's world famous pop-art painting. However, the result shown below is far from ... 
[image-processing] [generative-art]
 

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 52 votes

answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 67 votes

7.1.2.5 Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely.  This is really a question about three distinct things - to be done in Mathematica ... 
[equation-solving]
 

asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes

answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes

7.1.2.6 Conversion of Sine to Cosine

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521

I'm solving equations with many Cosines and Sines. 
And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). 
How can I do this? 
[trigonometry] [conversion]
 

asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes

7.1.2.7 Finding unit tangent, normal, and binormal vectors for a given r(t)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598

For my Calc III class, I need to find $T(t), N(t)$, and $B(t)$ for $t=1, 2$, and $-1$, given $r(t)=\{t,t^2,t^3\}$. 
 
I've got Mathematica, but I've never used it before and I'm not sure how to coerce ... 
[equation-solving] [calculus-and-analysis] [geometry] [vector-calculus] [homework]
 

asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 44 votes