Wikipedia:Reference desk/Archives/Mathematics/October 2010

= October 1 = Reference_desk/Archives/Mathematics/2010 October 1


 * 1) Transforming 3 points to a new coordinate plane in 3D Cartesian space
 * 2) Poincaré-Hopf Theorem
 * 3) basic combinatorics
 * 4) using CAS to find the catenary parameter a that will give us a curve that will pass through a given point

= October 2 = Reference_desk/Archives/Mathematics/2010 October 2


 * 1) more combinatorics
 * 2) Second moment of the binomial distribution
 * 3) More Limits

= October 3 = Reference_desk/Archives/Mathematics/2010 October 3


 * 1) k = x + 1/x
 * 2) Writing a puzzle
 * 3) Continued Fraction Factorisation Method - What is the point?

= October 4 = Reference_desk/Archives/Mathematics/2010 October 4


 * 1) Name the object
 * 2) Generalized Metric Space

= October 5 = Reference_desk/Archives/Mathematics/2010 October 5


 * 1) Trying to find a recent question in the archives
 * 2) Probability: number of die throws necessary to reach a certain probability of covering all numbers
 * 3) Truncated lognormal
 * 4) Probability

= October 6 = Reference_desk/Archives/Mathematics/2010 October 6


 * 1) combinatorial identity
 * 2) Stuck trying to prove a division problem
 * 3) include or not to include
 * 4) Optimal strategy for coin flipping game
 * 5) Set theory notation
 * 6) Minimal domain hash function
 * 7) Complete theory with a finite number of countable models

= October 7 = Reference_desk/Archives/Mathematics/2010 October 7


 * 1) More general form (and an image) for sine's continued fraction.
 * 2) binomial coeffcient
 * 3) hexagon torus
 * 4) Quick group theory question

= October 8 = Reference_desk/Archives/Mathematics/2010 October 8


 * 1) (1+z)/(1+conj(z))=z
 * 2) Asymptotic Distribution
 * 3) is this a true statement
 * 4) where is the difficulty?
 * 5) Principle of inclusion/exclusion
 * 6) Is there a strictly analytic way of solving complex number simplification problems?
 * 7) Taylor and MacLaurin series

= October 9 = Reference_desk/Archives/Mathematics/2010 October 9


 * 1) angle trisection
 * 2) Second Step Analysis for Markov Chains
 * 3) Biostatistics / math question
 * 4) Slope of a linear equation
 * 5) Probability

= October 10 = Reference_desk/Archives/Mathematics/2010 October 10


 * 1) Intersection of 2 dense subspaces of a normed vector space necessarily dense?
 * 2) Very straightforward probability
 * 3) A mirror problem

= October 11 = Reference_desk/Archives/Mathematics/2010 October 11


 * 1) Markov Chains
 * 2) Understanding the Double Dual
 * 3) Reverse Fourier
 * 4) Map from free abelian group onto the integers

= October 12 = Reference_desk/Archives/Mathematics/2010 October 12


 * 1) Rings with infinite height
 * 2) A simple exponentiation math problem

= October 13 = Reference_desk/Archives/Mathematics/2010 October 13


 * 1) a paradox?
 * 2) Laplace transform of a matrix?

= October 14 = Reference_desk/Archives/Mathematics/2010 October 14


 * 1) direction relative velocity

= October 15 = Reference_desk/Archives/Mathematics/2010 October 15


 * 1) Division by zero
 * 2) Variance
 * 3) Vector Fields and the Indices
 * 4) Coefficients in lengthy expansions
 * 5) could you explain cayley graph

= October 16 = Reference_desk/Archives/Mathematics/2010 October 16


 * 1) 1/n in base b
 * 2) Factorise this polynomial....
 * 3) Posterior distribution of lambda
 * 4) Series of bounded functions
 * 5) Improper Integral
 * 6) Final coordinate
 * 7) connect the opposite sides of a square with lines that don't cross

= October 17 = Reference_desk/Archives/Mathematics/2010 October 17


 * 1) human values

= October 18 = Reference_desk/Archives/Mathematics/2010 October 18


 * 1) Displacement –> Velocity
 * 2) trouble with differentiating something using only first principles
 * 3) Statistics
 * 4) how to refute someone's life work nicely
 * 5) The limit of sin x
 * 6) Combinatorics
 * 7) Test guessing Probability

= October 19 = Reference_desk/Archives/Mathematics/2010 October 19


 * 1) Quick query on field extension K-homomorphisms and isomorphisms
 * 2) More complex number trigonometry
 * 3) related to the question above
 * 4) Rectification
 * 5) how does arXiv work, or help with peer review?

= October 20 = Reference_desk/Archives/Mathematics/2010 October 20


 * 1) floor( exponential random variable ) = geometric distribution

= October 21 = Reference_desk/Archives/Mathematics/2010 October 21


 * 1) Formula for converting solid volume to liquid volume
 * 2) Bachmuth representation
 * 3) What is Mathematica doing?
 * 4) what do we know about large primes?

= October 22 = Reference_desk/Archives/Mathematics/2010 October 22


 * 1) Polynomial degree vs order
 * 2) typesetting a long stream of numbers in Latex?
 * 3) if you had to brute-force a number but could be told some of the digits
 * 4) Quotients
 * 5) Scenario: Traveling to Pandora as seen in James Cameron's movie Avatar
 * 6) Generalization of ordinals
 * 7) Shoelace formula
 * 8) Reducing Transformation Arrays
 * 9) GMAT scoring system
 * 10) Logic - deduction of axioms

= October 23 = Reference_desk/Archives/Mathematics/2010 October 23


 * 1) the four-color theorem doesn't seem right to me
 * 2) Help me impress my friend?
 * 3) secure hash
 * 4) terminology
 * 5) can you find an n-digit prime?

= October 24 = Reference_desk/Archives/Mathematics/2010 October 24


 * 1) Differentiate a function
 * 2) Finite subgroups of the multiplication group of the unit quaternions
 * 3) Does the position of the median change if a plot is distorted like this?
 * 4) Venn Diagram Word Problems
 * 5) Problem
 * 6) Choosing a pineapple at a supermarket

= October 25 = Reference_desk/Archives/Mathematics/2010 October 25


 * 1) Roulette
 * 2) Mentally generating random numbers
 * 3) complete the sequence
 * 4) Ergodicity

= October 26 = Reference_desk/Archives/Mathematics/2010 October 26


 * 1) Monomial Ordering
 * 2) Averaging points on a sphere
 * 3) prove that a + b will have the same value as b + a
 * 4) Linear transformation (map) problem, shortcut?
 * 5) physical constants as reported in Wikipedia

= October 27 = Reference_desk/Archives/Mathematics/2010 October 27


 * 1) Primitive roots modulo 5^n
 * 2) Standard error and standard deviation
 * 3) 1 = -1 ?
 * 4) how high do cryptographic functions scale (how big primes can you pick?)
 * 5) finding angles in 3D figures
 * 6) Clustering algorithm

= October 28 = Reference_desk/Archives/Mathematics/2010 October 28


 * 1) Obscure 3D shape that folds
 * 2) Another Logic query - uncountability
 * 3) Integral calculus
 * 4) Tough probability question
 * 5) Pairs of antihomologous points lie on a circle
 * 6) Fox calculus on [F', F']
 * 7) Differential equation
 * 8) property of primes

= October 29 = Reference_desk/Archives/Mathematics/2010 October 29


 * 1) binomial identity
 * 2) chance to win lotto in 70 years
 * 3) Endomorphisms of finite cyclic groups
 * 4) Normal subgroups of prime index
 * 5) getting the first four of the LAST 5 digits?  1234 from 12349
 * 6) what guarantee is there that numbers aren't very easy to factor (o(n))
 * 7) Conjecture

= October 30 = Reference_desk/Archives/Mathematics/2010 October 30


 * 1) Divisor of a Mersenne prime
 * 2) The mathematical spontaneity of coffee stirrers
 * 3) Algorithm for next term in series

= October 31 = Reference_desk/Archives/Mathematics/2010 October 31


 * 1) Pumping Lemma
 * 2) Analytic injective functions on the extended complex plane
 * 3) Lie Groups and Infinitesimal Actions
 * 4) Incorrectly named theorems