Wikipedia:Reference desk/Archives/Mathematics/January 2011

= January 1 = Reference_desk/Archives/Mathematics/2011 January 1


 * 1) Graph Theory

= January 2 = Reference_desk/Archives/Mathematics/2011 January 2


 * 1) Countable union of countable sets cannot have cardinality $aleph_2$
 * 2) Method of Characteristics

= January 3 = Reference_desk/Archives/Mathematics/2011 January 3


 * 1) Percentages and Probability

= January 4 = Reference_desk/Archives/Mathematics/2011 January 4


 * 1) statistics
 * 2) Permutations
 * 3) Identifying a quotient

= January 5 = Reference_desk/Archives/Mathematics/2011 January 5


 * 1) Special magic squares
 * 2) non-trivial irreducible character of primitive permutation character is faithful?
 * 3) Groups of order 24
 * 4) 1+1=2
 * 5) What constitutes a valid solution?
 * 6) Math and prejudice

= January 6 = Reference_desk/Archives/Mathematics/2011 January 6


 * 1) Tetrahedral angles
 * 2) Learning to read and write proofs
 * 3) Websites first postings
 * 4) Remainder term
 * 5) LaTeX

= January 7 = Reference_desk/Archives/Mathematics/2011 January 7


 * 1) Differentiation w/ respect to complex conjugate
 * 2) limit
 * 3) Question: what is the meaning of R suerscript n, subscript ++.
 * 4) distance measure
 * 5) What does it mean to raise big-O to a power?
 * 6) Inverse Function Theorem

= January 8 = Reference_desk/Archives/Mathematics/2011 January 8


 * 1) Pretty stupid question about statistics
 * 2) Cryptography
 * 3) Group theory: what is precise definition of A: B en A.B ?

= January 9 = Reference_desk/Archives/Mathematics/2011 January 9


 * 1) Alternate proof of the Weierstrass approximation theorem

= January 10 = Reference_desk/Archives/Mathematics/2011 January 10


 * 1) Godel sentences and the arithmetic hierarchy
 * 2) Groups
 * 3) Earth vs. human vs. rhinovirus

= January 11 = Reference_desk/Archives/Mathematics/2011 January 11


 * 1) Squared differences
 * 2) Series and Intergration
 * 3) How to visualize integer sequences?
 * 4) Adding paraboloids

= January 12 = Reference_desk/Archives/Mathematics/2011 January 12


 * 1) Maths competition puzzle
 * 2) Weird length issue
 * 3) 1 2 3 4 5 6 7 8 9 = 100
 * 4) cylindrical/spherical integration

= January 13 = Reference_desk/Archives/Mathematics/2011 January 13


 * 1) Coit tower
 * 2) Valid operations on cylindrical and spherical vectors
 * 3) Time dilation limit

= January 14 = Reference_desk/Archives/Mathematics/2011 January 14


 * 1) Gradients

= January 15 = Reference_desk/Archives/Mathematics/2011 January 15


 * 1) Sums of squares of normal random variables with the same distribution
 * 2) Sum of multipliers
 * 3) mathematical realism
 * 4) Reviving an old topic: Ambiguity in Number Theory

= January 16 = Reference_desk/Archives/Mathematics/2011 January 16


 * 1) Bases and spans for the space of infinite sequences $ell_2$
 * 2) Analytic geometry question
 * 3) Geostationary Satellite coordinate transformation
 * 4) "General Limit Theory"
 * 5) magic machine statistics

= January 17 = Reference_desk/Archives/Mathematics/2011 January 17


 * 1) continuous function on C equals zero somewhere
 * 2) math formula to computer formula
 * 3) Logical formula for existence of a path in a graph
 * 4) Is a group uniquely determined by the orders of its elements?
 * 5) How to read aloud the usual notation for the definite integral
 * 6) Probability of doubling up
 * 7) Use of Baire Category Theorem

= January 18 = Reference_desk/Archives/Mathematics/2011 January 18


 * 1) Calculating the probability that two binomial distributions are in order
 * 2) "sgn" in Latex
 * 3) Topology - Sequential spaces and sub sequential spaces
 * 4) Math game
 * 5) Mathematics and language
 * 6) Combination of error distributions

= January 19 = Reference_desk/Archives/Mathematics/2011 January 19


 * 1) Satisfiability Problem

= January 20 = Reference_desk/Archives/Mathematics/2011 January 20


 * 1) Finding limits using first principles
 * 2) Integration of vector-valued functions
 * 3) does this work?

= January 21 = Reference_desk/Archives/Mathematics/2011 January 21


 * 1) Vector calculus question

= January 22 = Reference_desk/Archives/Mathematics/2011 January 22


 * 1) Fibre Bundles and Actions
 * 2) Limit of a sequence of complex polynomials discontinuous at a single point
 * 3) sine function
 * 4) Filters in Topology
 * 5) Latus rectum of a parabola
 * 6) Polynomial approximation of a non-analytic complex function
 * 7) Latex: texorpdfstring with explicit superscript sign ^ in it
 * 8) Got stuck on a limit problem

= January 23 = Reference_desk/Archives/Mathematics/2011 January 23


 * 1) Tournament pairing question
 * 2) Quick question - showing an equation is insoluble (?)
 * 3) Number system that subtracts as well as adds

= January 24 = Reference_desk/Archives/Mathematics/2011 January 24


 * 1) z scores on a ti 84 plus
 * 2) Looking for a math word

= January 25 = Reference_desk/Archives/Mathematics/2011 January 25


 * 1) Integrable sets of functions
 * 2) Basic probability question
 * 3) Random function on the sphere

= January 26 = Reference_desk/Archives/Mathematics/2011 January 26


 * 1) Day of the week
 * 2) Geometrical symbol for midpoint, slope, and length
 * 3) my seperable diff eq general solution does not agree with the book

= January 27 = Reference_desk/Archives/Mathematics/2011 January 27


 * 1) Combine Standard Deviations

= January 28 = Reference_desk/Archives/Mathematics/2011 January 28


 * 1) Probability
 * 2) pls help
 * 3) The Stone Cech Compactification by Ultrafilters
 * 4) average in a class
 * 5) Learning R

= January 29 = Reference_desk/Archives/Mathematics/2011 January 29


 * 1) ZFC and its implications
 * 2) Constructing mathematical models.
 * 3) Ostensibly simple probability question?
 * 4) Taking from a large population without replacement

= January 30 = Reference_desk/Archives/Mathematics/2011 January 30


 * 1) First digits of 10^n
 * 2) Arc length proof
 * 3) Converting from rectangular to polar form
 * 4) Explanation of a few topology concents

= January 31 = Reference_desk/Archives/Mathematics/2011 January 31


 * 1) Start at different points, add 1. Evaluate evenness.
 * 2) Interchange of summation and differentiation with Fourier series
 * 3) Probabilistic Inclusion Exclusion.