3.26.2 Greatest hits from previous weeks

3.26.2.1 Finding Limits in several variables

http://mathematica.stackexchange.com/questions/21544/finding-limits-in-several-variables

 
Is there a way to find a limit of a multivariable function, like 
 
$$\lim_{(x,y)\to (0,0)} f(x,y)$$ 
with Mathematica? 
 
When $f$ is continuous, we can use 
$$\lim_{(x,y)\to (0,0)}  ...
 

- asked by Dominic Michaelis (21 votes), answered by whuber (32 votes)

3.26.2.2 Can Mathematica do symbolic linear algebra?

http://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra

 
For instance, is there some way I can say "let A and B be arbitrary real $m\times n$ and $k\times m$ matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? 
...
 

- asked by nikie (38 votes), answered by helen (19 votes)