2.8.2 Greatest hits from previous weeks

2.8.2.1 Even Fibonacci numbers

http://mathematica.stackexchange.com/questions/37266/even-fibonacci-numbers

 
Today, I found the Euler Project. Problem #2 is 
 
 
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 
 
1,  ...
 

- asked by Shutao TANG (26 votes), answered by rcollyer (34 votes)

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

http://mathematica.stackexchange.com/questions/8841/how-can-i-plot-the-direction-field-for-a-differential-equation

 
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  ...
 

- asked by Matt Groff (16 votes), answered by Peter Breitfeld (13 votes)