Wikipedia:Reference desk/Archives/Mathematics/April 2009

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April 1

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 1

1. Nonlinear ODEs with linear symmetries
2. Subgraph isomorphism in both directions implies isomorphism?
3. White noise

April 2

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 2

1. sorting quadratic irrationals with Maple 9
2. Plotting implicit functions
3. calendar question
4. Composed ceilings
5. Game theory terminology

April 3

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 3

1. Integral comparison text for a rather ugly function
2. mathematics-groups and rings
3. Really easy question
4. Fundamental Theorem of Algebra

April 4

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 4

1. Rolling hemispheres and moments of inertia
2. Kronecker Delta
3. Aleph numbers and the axiom of choice
4. Dyad
5. Repeated integration
6. Relations on a set X
7. What are the general equations to determine the xy locations of the points of a triangle when given the lengths of the 3 sides and the xy coordinates of one side?
8. Complex power series

April 5

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 5

1. A question
2. DNE
3. Largest Ordinal
4. Cubic Residues
5. Integral with one of its bounds appearing in the integrand

April 6

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 6

1. What is this called by definition
2. Maximal subgroups of a group
3. Divergence and Infinity
4. Just a quick answer check - volume integral
5. Testing hypotheses about ratings
6. Converting quadratic Bézier curve into cubic Bézier curve

April 7

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 7

1. "Measuring a rectangular box"

April 8

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 8

1. Combination?
2. Solving Congruences
3. unique left/right inverses for functions
4. Ratio and product distributions

April 9

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 9

1. Apollonian Circles
2. Inequality and greatest integer function
3. Number of combinations with constraints
4. Rule of Three expressed as a Mathematical Formula

April 10

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 10

1. x^y=y^x
2. Nontrivial Normal Abelian Subgroups of a Solvable Group

April 11

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 11

1. Limit involving moment generating functions
2. Graph
3. What symbol is this?
4. how does variable-length testing work?
5. why does modulus of a random integer in a high range favor lower answers SO SLIGHTLY?
6. okay then what is the answer
7. how to do monte carlo properly

April 12

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 12

1. When (or how do i find out when) the integral of x^P exp(-x^Q) converges over (0, infinity)?
2. Intrinsic equation
3. Invariant sets
4. Factorial proof
5. Conjugate Diameter?
6. Mandelbrot Set

April 13

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 13

1. Length of a Continued Fraction
2. constructing a table
3. Gaussian Derivative
4. Polynomial question/thing
5. statistics: are there real effects that are impossible to show statistically with very high confidence?
6. Finding P
7. Connection between frequency modulation and Bessel functions

April 14

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 14

1. Puzzle
2. What is $intsqrt{1-frac{dt^{2}}{dr^{2}}}dr$?
3. Repeated Root

April 15

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 15

1. Composition of functions and integrability
2. Isolated singularities
3. Algebra: Olympiad question

April 16

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 16

1. Prime number
2. water disturbance equation

April 17

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 17

1. Is there an infinite number of different types of probability distribution?
2. Functional form of the von-Neumann Morgenstern utility function - any help much appreciated!!!
3. Class number 1

April 18

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 18

1. Conditional probability in LaTeX
2. Uniform population sampling noise
3. (n-1)-size linearly independent subsets of n vectors
4. Is a given set of group elements a set of coset representatives?
5. Critical graph

April 19

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 19

1. Splitting lemma

April 20

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 20

1. Topological properties
2. Simplifying logarithms with Maxima
3. 1. Nf3 f5 2. d4 e6 3. Bg5 Be7 4. Bxe7 Qxe7
4. Numbered system of equations in LaTeX

April 21

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 21

1. A*B*C = B cubed – B, where A, B and C are successive integers?
2. Quantum mechanics?

April 22

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 22

1. The Floor Function
2. Factoring a cubic
3. apparent error in pages on kernel smoothing

April 23

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 23

1. In geometry, is a square with rounded corners still considered a square? If not, what is it called, mathematically?
2. Quotient spaces, and cell complexes

April 24

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 24

1. Growth of a bacterial colony
2. sci.mathresearch newsreader question
3. Polynomial division
4. Holomorphic mapping
5. How to compute statistical significance of correlation

April 25

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 25

1. higher derivatives
2. dice
3. Poker theory and cardless poker
4. A large slice of pie
5. Upper bound on the number of topologies of a finite set
6. Homework problem

April 26

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 26

1. Convert a computer file to a non-negative Integer number
2. Birthday paradox
3. The Gateaux derivative - how is it defined?
4. Pólya enumeration theorem
5. Example in the article about the Hermite interpolation
6. Digit distribution

April 27

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 27

1. The Greatest Integer Function
2. Why is "dense-in-itself" a useful notion?
3. Proving or disproving a homeomorphism with [0,1]
4. Can every unit algebraic number be expressed as a root of unity?
5. Disjoint balls into a ball in R^n

April 28

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 28

1. Łukasiewicz notation for propositional functions
2. Easy probability question
3. The set of complex numbers is the largest possible set of numbers?

April 29

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 29

1. Evaluating very small natural logs
2. Integral - confusion

April 30

Wikipedia:Reference_desk/Archives/Mathematics/2009 April 30

1. house payment