Wikipedia:Reference desk/Archives/Mathematics/May 2009

= May 1 = Reference_desk/Archives/Mathematics/2009 May 1


 * 1) Pairing colours, permutations and such
 * 2) Complex integral
 * 3) Exponential Addition

= May 2 = Reference_desk/Archives/Mathematics/2009 May 2


 * 1) Derivatives of functions of more than one variable
 * 2) Binomial expansion
 * 3) Essential singularity
 * 4) calculating rate constant k

= May 3 = Reference_desk/Archives/Mathematics/2009 May 3


 * 1) How to make my own do it yourelf leading indicator?
 * 2) What's going on here?
 * 3) Adjusting a statistical snapshot for duration
 * 4) Applications of Conway's cosmological theorem

= May 4 = Reference_desk/Archives/Mathematics/2009 May 4


 * 1) Application of Differentiation
 * 2) Penney's Game
 * 3) decimal to HEX

= May 5 = Reference_desk/Archives/Mathematics/2009 May 5


 * 1) Möbius strip
 * 2) A couple probability questions about points on a sphere
 * 3) Arclength of tan from pi eigths to pi fourths
 * 4) Rational points on a circle

= May 6 = Reference_desk/Archives/Mathematics/2009 May 6


 * 1) Limits of differentiable functions
 * 2) Cycloid
 * 3) how to do monte carlo for statistics?
 * 4) Non-discrete valuation ring
 * 5) Group homomorphisms
 * 6) for Buffon's needle does the length of the needle not matter

= May 7 = Reference_desk/Archives/Mathematics/2009 May 7


 * 1) Chaitin version of Gödel incompleteness theorem
 * 2) bijection between RXR and R
 * 3) why does having a unique right inverse for some function f imply bijectivity while having a unique left inverse doesn't?
 * 4) List of functional analysis topics
 * 5) statistics: is 98% confidence the same as 98% of cases out a billion?
 * 6) 1 +1 ?
 * 7) trigonometric functions
 * 8) Arcs and Radii
 * 9) Harmony in music based on periodic waveforms
 * 10) Division of exponential random variables
 * 11) Theorem guaranteeing minimum value of bounded function

= May 8 = Reference_desk/Archives/Mathematics/2009 May 8


 * 1) A derivative of the log of sigmoidal functions
 * 2) Mathematics - Sequence analysis
 * 3) trigonometric conversions
 * 4) what does statistical confidence MEAN
 * 5) what good are sins and cosins and all that stuff
 * 6) someone above said 98% of cases out of a billion isn't 98% confidence -- why
 * 7) Calculation problem including vector
 * 8) factoring integers in polynomial time
 * 9) Z-hat

= May 9 = Reference_desk/Archives/Mathematics/2009 May 9


 * 1) Gradient of linear graph
 * 2) okay, is THIS confidence?
 * 3) Logistic equation vs logistic map
 * 4) MLS Matrix transformation

= May 10 = Reference_desk/Archives/Mathematics/2009 May 10


 * 1) Suggestion for a good book on axiomatic set theory
 * 2) Numerical Methods for Solving PDEs
 * 3) Means
 * 4) Top mathematical journals
 * 5) Simple vector equation: most general solution
 * 6) Areas of circles
 * 7) bicycling paradox

= May 11 = Reference_desk/Archives/Mathematics/2009 May 11


 * 1) Curvature question
 * 2) do number of consecutive misses of coin toss follow normal distribution? What is the standard deviation?
 * 3) Change of variables in 3 dimensions - please help!

= May 12 = Reference_desk/Archives/Mathematics/2009 May 12


 * 1) Countable axiom of choice--is it consistent with Axiom of Determinacy
 * 2) Binary relations and equivalent conditions = Argh

= May 13 = Reference_desk/Archives/Mathematics/2009 May 13


 * 1) What are the benefits to humans of using a tree structure?
 * 2) Second difference equation
 * 3) Does mathematics exist in an empty universe?
 * 4) Triangle areas
 * 5) Finding an approximation to a linear system
 * 6) 7 tens

= May 14 = Reference_desk/Archives/Mathematics/2009 May 14


 * 1) how many possible soduko variations are there
 * 2) geometry and algebra
 * 3) Limit of sequence
 * 4) Rate of change
 * 5) Totally real fields
 * 6) Question from a mechanics past paper

= May 15 = Reference_desk/Archives/Mathematics/2009 May 15


 * 1) shape of solution space
 * 2) logarithm
 * 3) Fatou's Lemma and liminfs
 * 4) Irrationality of Pi

= May 16 = Reference_desk/Archives/Mathematics/2009 May 16


 * 1) Correcting linear least squares coefficients for small samples
 * 2) Showing an element is irreducible
 * 3) Proof that n orthogonal vectors form a basis for $\mathbb{R}^n$?

= May 17 = Reference_desk/Archives/Mathematics/2009 May 17
 * 1) does anyone know how to solve these?
 * 2) Fairly simple $\nabla$/inequality problem
 * 3) LaTeX fraction spacing

= May 18 = Reference_desk/Archives/Mathematics/2009 May 18


 * 1) Decomposition of a symmetric matrix
 * 2) how many spheres diam D1 can pack on the surface of a larger sphere diam D2
 * 3) What is the ratio of the area of a circle to a square
 * 4) 90 Degree Angle

= May 19 = Reference_desk/Archives/Mathematics/2009 May 19


 * 1) Lifting prime ideals to integral extensions
 * 2) Name that theorem...
 * 3) Exponential functions multi-valued?

= May 20 = Reference_desk/Archives/Mathematics/2009 May 20


 * 1) Goldbach conjecture
 * 2) Parimutuel betting
 * 3) transcendental equation
 * 4) does anyone know how to solve this????

= May 21 = Reference_desk/Archives/Mathematics/2009 May 21


 * 1) concentric circles
 * 2) Spheres in an n-dimensional sphere
 * 3) joint probability distribution terminology

= May 22 = Reference_desk/Archives/Mathematics/2009 May 22


 * 1) HOW HE DID IT?
 * 2) probability book?
 * 3) Maximum Volume of Cone made from cut sector of a circle.
 * 4) working out foot pound ratio for powder in grams

= May 23 = Reference_desk/Archives/Mathematics/2009 May 23


 * 1) A LaTeXnicality
 * 2) Probability of dots on a circumferance

= May 24 = Reference_desk/Archives/Mathematics/2009 May 24


 * 1) Margin vs Markup
 * 2) value of pi
 * 3) Nonlinear Homogeneous Differential Equations
 * 4) Plus-or-minus range

= May 25 = Reference_desk/Archives/Mathematics/2009 May 25


 * 1) New Elementary Suggestive Results Found By Birthday Coincidences Related To History
 * 2) Proving in equality
 * 3) perfect squares
 * 4) conformal bijective map
 * 5) Finding cube root

= May 26 = Reference_desk/Archives/Mathematics/2009 May 26


 * 1) Statistical fallacies in White Nationalist propaganda?
 * 2) Nicer proof of Stirling's approximation
 * 3) Bijection between R and C
 * 4) Novel Problem Related To Research
 * 5) Published puzzle
 * 6) Diffeology
 * 7) Implicit differentiation problem

= May 27 = Reference_desk/Archives/Mathematics/2009 May 27


 * 1) Chess openings
 * 2) Notation for derivatives ?
 * 3) Convergence of the series z^(n!)

= May 28 = Reference_desk/Archives/Mathematics/2009 May 28


 * 1) Wolfram Alpha exponentiation quirk?
 * 2) Solving for a matrix...

= May 29 = Reference_desk/Archives/Mathematics/2009 May 29


 * 1) How many different types of six sided dice are there?
 * 2) Analytical Continuation

= May 30 = Reference_desk/Archives/Mathematics/2009 May 30


 * 1) Eulerian city?

= May 31 = Reference_desk/Archives/Mathematics/2009 May 31


 * 1) Lottery question
 * 2) Parentheses and functions
 * 3) Mathematical Drawing