# New in *MathWorld* -- April
2004

### Friday April 30, 2004

- Folium (modified)
- Folium of Descartes (modified)
- Freeth's Nephroid (modified)
- Gear Curve (modified)
- Hippopede (modified)
- Hyperbola (modified)
- Hyperbola Inverse Curve (modified)
- Hyperbolic Spiral (modified)
- Hypocycloid Pedal Curve (modified)
- Kepler's Folium (modified)
- Knot Curve (modified)
- Wave Equation (modified)
- Wave Equation--1-Dimensional
- Wave Equation--Rectangle
- Wave Equation--Triangle

### Thursday April 29, 2004

- Delta Function (modified)
- Kampyle of Eudoxus (modified)
- Smarandache Function (modified)

### Wednesday April 28, 2004

- Catalan Number (modified)

### Tuesday April 27, 2004

- Colimit
- Direct Limit (modified)
- Ideal Class
- Inverse Limit (modified)
- Kampyle of Eudoxus (modified)
- Krasner's Lemma
- Non-Archimedean Valuation

### Monday April 26, 2004

- Aliquot Divisor (modified)
- Catalan Number (modified)
- Dürer's Conchoid (modified)
- Eight Curve (modified)
- Ellipse (modified)
- Ellipse Involute (modified)
- Epicycloid Pedal Curve (modified)
- Preorder
- Quasiorder

### Sunday April 25, 2004

- Area (modified)
- Circle Inverse Curve
- Circle Orthotomic (modified)
- Circle Pedal Curve (modified)
- Circle Radial Curve (modified)
- Cycloid Radial Curve (modified)
- Deltoid Involute (modified)
- Deltoid Pedal Curve (modified)
- Deltoid Radial Curve (modified)
- Dumbbell Curve (modified)
- Minkowski's Lemma
- Vecten Points (modified)

### Saturday April 24, 2004

- Rhombus (modified)

### Friday April 23, 2004

- Common Logarithm (modified)
- Lg (modified)
- Logarithm (modified)
- Nested Logarithm

### Thursday April 22, 2004

- Bernoulli Number (modified)
- Capacity Dimension (modified)
- Clean Tile Problem
- Correlation Dimension (modified)
- Disk Line Picking (modified)
- Fibonacci Q-Matrix (modified)
- Gamma Distribution (modified)
- Hurwitz Zeta Function (modified)
- Information Dimension (modified)
- Irregular Prime (modified)
- Octahedron Tetrahedron Picking
- Smarandache Function (modified)
- Spiral (modified)
- von Staudt-Clausen Theorem (modified)

### Wednesday April 21, 2004

- Binomial Coefficient (modified)
- Cylinder (modified)
- Isomorphism (modified)
- Iverson Bracket (modified)
- k-Subset (modified)
- Logarithmic Integral (modified)
- n-Tuple (modified)
- Piecewise
- Piecewise Function
- Sokhotsky's Formula (modified)
- Soldner's Constant (modified)
- Sphere (modified)
- String (modified)
- Subset (modified)
- Subsets
- Symmetric Polynomial (modified)
- Unit Matrix (modified)

### Tuesday April 20, 2004

- Absolute Square (modified)
- Alternating Group (modified)
- Ball Picking
- Bessel Function of the Second Kind (modified)
- Bézout's Theorem (modified)
- Braid (modified)
- Dixon-Ferrar Formula (modified)
- Farkas's Lemma (modified)
- Favard Constants (modified)
- Isomorphism (modified)
- Jordan Canonical Form (modified)
- Level Set (modified)
- Maltitude (modified)
- Matrix Polynomial (modified)
- Maurer Rose (modified)
- Moment-Generating Function (modified)
- Near Noble Number (modified)
- Noble Number (modified)
- Traveling Salesman Constants (modified)
- Unknown

### Monday April 19, 2004

- Arithmetic Progression (modified)
- Braid Group (modified)
- Braid Word (modified)
- Checker-Jumping Problem (modified)
- Complexity (modified)
- Conway's Soldiers (modified)
- Integer Complexity (modified)
- Minimal Banach Space (modified)
- Nine-Point Center (modified)
- Square (modified)
- Triangle (modified)
- Triangle Triangle Erecting
- Vecten Points

### Sunday April 18, 2004

- Angle Bisector (modified)
- Catenary Evolute (modified)
- Catenary Radial Curve (modified)
- Cayley's Sextic Evolute (modified)
- Exterior Angle (modified)
- Exterior Angle Bisector (modified)
- External Angle Bisector
- Internal Angle Bisector

### Saturday April 17, 2004

- Astroid Evolute (modified)
- Astroid Involute (modified)
- Bean Curve (modified)
- Cardioid Evolute (modified)
- Cardioid Involute (modified)
- Cardioid Negative Pedal Curve (modified)
- Cardioid Pedal Curve (modified)
- Cayley's Sextic (modified)

### Friday April 16, 2004

- Archimedean Spiral (modified)
- Astroid (modified)
- Astroid Catacaustic
- Astroid Pedal Curve (modified)
- Astroid Radial Curve (modified)
- Disk Triangle Picking (modified)
- Gauss's Circle Problem (modified)
- Lebesgue Minimal Problem (modified)
- Legendre's Constant (modified)
- Line Picking
- Line Segment Picking
- Simplex Simplex Picking (modified)
- Totient Function (modified)
- Trigonometry Angles (modified)

### Thursday April 15, 2004

- Balanced Binomial Coefficient (modified)
- Ball Triangle Picking (modified)
- Binomial Coefficient (modified)
- Bracketing (modified)
- Conchospiral
- Nested Function (modified)
- Polygon Triangle Picking (modified)
- Sylvester's Four-Point Problem (modified)
- Triangle Point Picking (modified)

### Wednesday April 14, 2004

- Arithmetic Progression (modified)
- Arithmetic Sequence (modified)
- Butterfly Curve (modified)
- Debye's Asymptotic Representation (modified)
- Extremum (modified)
- Fourier Series--Power (modified)
- Gödel Number (modified)
- Harmonic Series (modified)
- Newton-Cotes Formulas (modified)
- Rule of 72 (modified)
- Trigonometry Angles--Pi/11 (modified)

### Tuesday April 13, 2004

- Additive Polynomial
- Algebraic Identity
- Arc Length (modified)
- Bifoliate (modified)
- Bifolium (modified)
- Ferrari's Identity (modified)
- Folium (modified)
- Kepler's Folium (modified)
- Quadrifolium (modified)
- Reciprocal Fibonacci Constant (modified)
- Trifolium (modified)
- Zariski Topology (modified)

### Monday April 12, 2004

- Conway's Soldiers
- Dirichlet Kernel (modified)
- Erdős-Turán Conjecture
- Hurwitz Zeta Function (modified)
- Prime Arithmetic Progression (modified)
- Riemann Zeta Function (modified)
- Solitaire Army
- Szemerédi's Theorem (modified)

### Saturday April 10, 2004

- 4/n Problem (modified)
- Dissection (modified)
- Elder's Theorem (modified)
- Penrose Tiles (modified)
- Stanley's Theorem (modified)

### Friday April 9, 2004

- Hurwitz Zeta Function (modified)
- Maximum (modified)
- Minimum (modified)
- Paired t-Test (modified)
- Riemann Zeta Function (modified)
- Witch of Agnesi (modified)

### Thursday April 8, 2004

- Adjoint (modified)
- Adjoint Matrix (modified)
- Champernowne Constant (modified)
- Closed Graph Theorem (modified)
- Complex Conjugate (modified)
- Computational Irreducibility (modified)
- Concatenation Sequence
- Conjugate Transpose (modified)
- Consecutive Number Sequences (modified)
- Dagger (modified)
- Ideal (modified)
- Interior (modified)
- Isometry Element
- Projection Matrix (modified)
- Ramanujan Constant (modified)
- Transpose (modified)

### Wednesday April 7, 2004

- Approximate Unit
- Banach Algebra (modified)
- Banach Completion
- Banach Space (modified)
- Bounded Approximation Property (modified)
- Bounded Left Approximate Identity
- Carl Neumann Criterion
- Co-Isometry
- Contractible (modified)
- Contractible Banach Algebra
- C^*-Algebra Representation
- Dual Normed Space (modified)
- Essential Ideal
- Essentially Unitary
- Exterior Angle (modified)
- Gelfand Mazur Theorem
- Hereditary C^*-Subalgebra
- Involutive Algebra
- Involutive Banach Algebra
- Minimal Banach Space (modified)
- Multiplier Algebra
- Normal Element
- Partial Isometry Element
- Path Integral (modified)
- Polar Decomposition
- Positive Element
- Positive Linear Functional
- Positive Map
- Pre-C^*-Algebra
- Principle of Uniform Boundedness
- Random Matrix (modified)
- Self-Adjoint Element
- Star-Homomorphism
- State
- Unitarily Equivalent
- Unitary Element
- Unit Circle (modified)
- Unit Disk (modified)
- Unitization
- von Neumann Algebra (modified)
- W^*-Algebra

### Tuesday April 6, 2004

- Jack Polynomial
- Monomial (modified)
- Random Matrix (modified)
- Real Matrix (modified)
- Symmetric Polynomial (modified)
- Wigner's Semicircle Law

### Saturday April 3, 2004

- Kac Formula (modified)
- Prime Sums (modified)

### Friday April 2, 2004

- Binomial Distribution (modified)
- Capacity Dimension (modified)
- Correlation Dimension (modified)
- Discrete Uniform Distribution (modified)
- Equally Likely Outcomes Distribution (modified)
- Exterior Angle (modified)
- Geometric Distribution (modified)
- Negative Binomial Distribution (modified)
- Normal Distribution (modified)
- Octagon (modified)
- Poisson Distribution (modified)
- StudentTDistribution
- Truncated Icosahedron (modified)
- Uniform Distribution (modified)
- Vertex Angle (modified)

### Thursday April 1, 2004

- Banach Algebra (modified)
- B^*-Algebra (modified)
- Circle Line Picking (modified)
- Circle Triangle Picking (modified)
- Computational Irreducibility (modified)
- C^*-Algebra (modified)
- Differential Equation Symmetry
- Disk Point Picking (modified)
- Disk Triangle Picking (modified)
- Dual Normed Space
- Dual Space (modified)
- Dual Vector Space (modified)
- Gaussian Triangle Picking
- Octahedral Group (modified)
- Prelle-Singer Method
- Rudin-Shapiro Sequence (modified)
- Tetrahedral Group (modified)
- von Neumann Algebra (modified)

[ 2024 ▪ 2023 ▪ 2022 ▪ 2021 ▪ 2020 ▪ 2019 ▪ 2018 ▪ 2017 ▪ 2016 ▪ 2015 ▪ 2014 ▪ 2013 ▪ 2012 ▪ 2011 ▪ 2010 ▪ 2009 ▪ 2008 ▪ 2007 ▪ 2006 ▪ 2005 ▪ 2004 ▪ 2003 ▪ 2002 ▪ 2001 ▪ 2000 ▪ 1999 ]