DanielV

 182 'Obvious' theorems that are actually false 82 “Which answer in this list is the correct answer to this question?” 62 Why do negative exponents work the way they do? 59 Is there a law that you can add or multiply to both sides of an equation? 55 Why does $\sqrt{n\sqrt{n\sqrt{n \ldots}}} = n$?

### Reputation (18,557)

 +10 Proving a Boolean expression. +15 How can I prove that $\frac{n^2}{x_1+x_2+\dots+x_n} \le \frac{1}{x_1}+ \frac{1}{x_2} +\dots+ \frac{1}{x_n}$? +50 Gödel's paradox: Why is “a proof that some universal statement is unprovable” not a valid proof that this statement is true? +10 Recurrence series with matrix for $a_n=a_{n-1}-2a_{n-2}$

### Questions (16)

 7 Are there any documented logics that use transitivity of implication rather than modus ponens as a primitive? 6 Element of a Singleton (set with one element) notation 3 Constructive logic vs classic logic for $\vdash A \iff B$ 2 Terminology for free variables 2 Name for functions whose outputs are larger than inputs

### Tags (264)

 351 logic × 223 80 puzzle × 15 221 algebra-precalculus × 55 77 linear-algebra × 52 184 soft-question × 34 75 matrices × 36 107 sequences-and-series × 34 72 probability × 31 97 discrete-mathematics × 74 68 recurrence-relations × 51