smackcrane

 16 Average of multiple vectors 12 There exist an infinite subset $S\subseteq\mathbb{R}^3$ such that any three vectors in $S$ are linearly independent. 9 Percentage of primes among the natural numbers 8 Converting multiplying fractions to sum of fractions 8 Closed formula for entries of “Pascal's half triangle”

### Reputation (2,351)

 +10 Find the number of all four-digit positive integers that are divisible by four and are formed by the digits 0,1,2,3,4,5 +5 How does one calculate genus of an algebraic curve? +10 Closed formula for entries of “Pascal's half triangle” +5 if $S$ is a ring (possibly without identity) with no proper left ideals, then either $S^2=0$ or $S$ is a division ring.

### Questions (15)

 23 How does one calculate genus of an algebraic curve? 10 Can continuity be proven in terms of closed sets? 10 The preimage of a maximal ideal is maximal 9 How to show that the ring $S/A$ has no zero divisors? (Hungerford, Algebra, Problem 12, Chapter III, Section 2) 8 Polynomials vanishing on an infinite set

### Tags (54)

 18 linear-algebra × 6 14 elementary-number-theory × 2 17 vector-spaces × 2 13 probability × 9 16 calculus × 8 12 algebra-precalculus × 4 16 average 9 prime-numbers 15 combinatorics × 5 8 partial-fractions

### Accounts (9)

 Mathematics 2,351 rep 11627 Stack Overflow 1,005 rep 816 Skeptics 304 rep 24 Mathematica 151 rep 3 Area 51 151 rep