7.5.2 Greatest hits from previous weeks

7.5.2.1 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

7.5.2.2 Extract real part of a complex expression better than Re does

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306

I have a complex expression with real positive variables only. 
 
Mathematica Input Style: 
 
... 
[symbolic] [trigonometry]
 

asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes

answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 53 votes

7.5.2.3 Assign the results from a Solve to variable(s)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669

I understand Mathematica can't assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables? 
... 
[equation-solving] [assignment] [faq]
 

asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 56 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 34 votes

7.5.2.4 Why round to even integers?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116

According to the Mathematica help: 
Round rounds numbers of the form x.5 toward the nearest even integer. 
For example: 
 
 Round[{0.5, 1.5, 2.5, 3.5, 4.5}] 
 
 
gives 
... 
[numerics] [language-design]
 

asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 83 votes

answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 51 votes

7.5.2.5 Using Export[] sends the file where?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586

I am trying to use the  Export  command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can't find the file! Where is it ... 
[export]
 

asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes

7.5.2.6 Formatting legend text font

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433

I am using this code to plot a graph, and I am trying to make the font of the legend bigger. 
 
... 
[plotting] [legending] [labeling]
 

asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes

7.5.2.7 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