Wikipedia:Reference desk/Archives/Mathematics/December 2009

= December 1 = Reference_desk/Archives/Mathematics/2009 December 1


 * 1) Exponential or Super-Exponential Growth In A Novel Sequence
 * 2) negative exponent dividend
 * 3) steps and results of simplification
 * 4) Transpose
 * 5) Cyclic hexagon
 * 6) $mathbb{Z}_n[x]$ in GAP

= December 2 = Reference_desk/Archives/Mathematics/2009 December 2


 * 1) Sets and the absolute infinite
 * 2) A strange puzzle
 * 3) Absolute Levi-Civita

= December 3 = Reference_desk/Archives/Mathematics/2009 December 3


 * 1) If ab = ac, then b = c.
 * 2) Growth of Log and Power

= December 4 = Reference_desk/Archives/Mathematics/2009 December 4


 * 1) Same Question As Three Days Ago, But In The Other Direction
 * 2) Quick Q about $e^{i pi} + 1 = 0, ,!$
 * 3) minima help please
 * 4) Naive or automatic forecasting from multivariate time-series
 * 5) Infinite roots
 * 6) Borel sets
 * 7) Paper folding

= December 5 = Reference_desk/Archives/Mathematics/2009 December 5


 * 1) optimisation tric??
 * 2) Probability of object being owned by person
 * 3) Speed calculation

= December 6 = Reference_desk/Archives/Mathematics/2009 December 6


 * 1) A Related Problem In Base Four
 * 2) finite differentiation
 * 3) Integral

= December 7 = Reference_desk/Archives/Mathematics/2009 December 7


 * 1) random 8 digit number reads the same both ways

= December 8 = Reference_desk/Archives/Mathematics/2009 December 8


 * 1) Standard form
 * 2) Geometric argument for area under x2

= December 10 = Reference_desk/Archives/Mathematics/2009 December 10


 * 1) sudoku
 * 2) Integral estimate

= December 11 = Reference_desk/Archives/Mathematics/2009 December 11


 * 1) weighted mean and errors
 * 2) Non-linear ODE question

= December 12 = Reference_desk/Archives/Mathematics/2009 December 12


 * 1) Is This Problem Intractable?
 * 2) Expectation
 * 3) Convergence of the boundary for this series
 * 4) STEP papers
 * 5) A very simple question

= December 13 = Reference_desk/Archives/Mathematics/2009 December 13


 * 1) Did the Mayans or Babylonians invent zero first?
 * 2) More on finite differences

= December 14 = Reference_desk/Archives/Mathematics/2009 December 14


 * 1) Numbers
 * 2) Cardinal Ordinal
 * 3) Indistinguishable balls in distinguishable boxes

= December 15 = Reference_desk/Archives/Mathematics/2009 December 15


 * 1) Isoperimetric yard problem
 * 2) rotated figure
 * 3) Question in computing probabilities
 * 4) Logarithms and Conic Sections.
 * 5) Normal variables, independence, covariance

= December 16 = Reference_desk/Archives/Mathematics/2009 December 16


 * 1) Multiply Intrinsically 4-Palindromic Numbers
 * 2) Finite differences of factorials
 * 3) combinatorics (pigenhole etc)
 * 4) Distributivity
 * 5) double-checking statistics
 * 6) items arranged question

= December 17 = Reference_desk/Archives/Mathematics/2009 December 17


 * 1) recognition of tangent plane for a function
 * 2) Easiest way to decide if a point is within a polygon?
 * 3) Are the slopes of $f(x)$ and $f^{-1}(x)$ necessarily reciprocal?

= December 18 = Reference_desk/Archives/Mathematics/2009 December 18


 * 1) Non-isomorphic digraphs
 * 2) Continuous or not?

= December 19 = Reference_desk/Archives/Mathematics/2009 December 19


 * 1) Differentiability of a function from R^2 to R at the origin
 * 2) Distance from a point to a line
 * 3) Plotting a fractal curve defined by binary digits

= December 20 = Reference_desk/Archives/Mathematics/2009 December 20


 * 1) hyperbolic tangent derivative
 * 2) Local class field theory
 * 3) New Identity?
 * 4) Rouché's theorem
 * 5) Matrix subgroups

= December 21 = Reference_desk/Archives/Mathematics/2009 December 21


 * 1) Calculus History
 * 2) Fréchet Second Derivatives and Taylor Series of matrix functions
 * 3) Vector cosine
 * 4) Calculi(Non Newtonian)
 * 5) Article introducing complex numbers
 * 6) Principles of Mathematics
 * 7) Reducible Polynomials With All But Constant Coefficient Equalling 1
 * 8) googol

= December 22 = Reference_desk/Archives/Mathematics/2009 December 22


 * 1) Desperately Seeking a Faster Algorithm
 * 2) Summation of finite differences
 * 3) Stationary Points in Higher Dimensions
 * 4) Symbol for 'such that'
 * 5) Cartoon books about mathematics

= December 23 = Reference_desk/Archives/Mathematics/2009 December 23


 * 1) Functional Analysis
 * 2) reduction algorithm
 * 3) 120 links between five people??
 * 4) Why does a*b give the area of a rectangle? / Why does arithmetic give meaningful geometric results?

= December 24 = Reference_desk/Archives/Mathematics/2009 December 24


 * 1) Green's second identity and Green's functions for the Laplacian
 * 2) sequence space
 * 3) Rolling sphere

= December 25 = Reference_desk/Archives/Mathematics/2009 December 25


 * 1) Easy way of deciding if two lines cross?

= December 26 = Reference_desk/Archives/Mathematics/2009 December 26


 * 1) dual spaces of Sobolev spaces
 * 2) Is the word "induce" used technically or non-technically?
 * 3) Does U(1) = SU(1)
 * 4) Linear combination of matrices
 * 5) Algebra over a ring that is a field?

= December 27 = Reference_desk/Archives/Mathematics/2009 December 27


 * 1) Algorithm to reduce polynary equations to minimum form
 * 2) Measure Theory & Countability
 * 3) Math and calculations
 * 4) Limit of a sequence
 * 5) Computationally expensive problems
 * 6) The all-ones vector, and how to notate it

= December 28 = Reference_desk/Archives/Mathematics/2009 December 28


 * 1) Lebesgue measure versus Borel measure
 * 2) Universal enveloping algebra
 * 3) How to solve math poblems without calculating
 * 4) Sum and Difference of Two Tangents

= December 29 = Reference_desk/Archives/Mathematics/2009 December 29


 * 1) Hypervolume of an 8-sphere
 * 2) transcendental functions
 * 3) No math after 12th grade?
 * 4) Symmetries and perturbations

= December 30 = Reference_desk/Archives/Mathematics/2009 December 30


 * 1) non polynomial difference
 * 2) Calculate my age as percentage of USA age.
 * 3) Solving for x giving the min
 * 4) 'Reproducing generations problem' or 'sum of 2 to the power n'

= December 31 = Reference_desk/Archives/Mathematics/2009 December 31


 * 1) Ryan's hypo-whatsisis?
 * 2) Gauss–Jordan elimination = reduced row echelon form?
 * 3) Some basic topology of the torus
 * 4) Looking for random "shopping" algorithm