Wikipedia:Reference desk/Archives/Mathematics/2014 October 28

= October 28 =

Catalan number
Can someone explain Catalan numbers more simplistically than our article does? Why they work the way they do for example. Thanks, Dismas |(talk) 08:53, 28 October 2014 (UTC)


 * This pdf might help you. It explains the connections between various problems whose solutions involve the Catalan numbers, and derives some of the properties of Catalan numbers. A key property is the recurrence relation


 * $$C_{n+1} = \sum^{n}_{m=0}C_m C_{n-m}$$


 * Gandalf61 (talk) 17:40, 31 October 2014 (UTC)

Situations where indeterminate forms are NOT considered indeterminate
The article indeterminate form says 0 time infinity is indeterminate. However, in the Extended real number line article, it says that for some purposes, 0 times infinity is unambiguously 0, and thus not indeterminate. Can anyone edit the indeterminate form article to make it include situations like these?? Georgia guy (talk) 18:17, 28 October 2014 (UTC)
 * There's nothing to edit. Yes, sometimes it's useful to define $$0\times \infty = 0$$, but not in the context of evaluating limits.--80.109.80.31 (talk) 19:16, 28 October 2014 (UTC)