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Conical Helix
In mathematics, a conical spiral, also known as a conical helix, is a space curve on a right circular cone, whose Orthographic projection, floor projection is a plane spiral. If the floor projection is a logarithmic spiral, it is called ''conchospiral'' (from conch). Parametric representation In the x-y-plane a spiral with parametric representation : x=r(\varphi)\cos\varphi \ ,\qquad y=r(\varphi)\sin\varphi a third coordinate z(\varphi) can be added such that the space curve lies on the cone with equation \;m^2(x^2+y^2)=(z-z_0)^2\ ,\ m>0\; : * x=r(\varphi)\cos\varphi \ ,\qquad y=r(\varphi)\sin\varphi\ , \qquad \color \ . Such curves are called conical spirals. They were known to Pappos. Parameter m is the slope of the cone's lines with respect to the x-y-plane. A conical spiral can instead be seen as the orthogonal projection of the floor plan spiral onto the cone. Examples : 1) Starting with an ''archimedean spiral'' \;r(\varphi)=a\varphi\; gives the conical spiral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermat's Spiral
A Fermat's spiral or parabolic spiral is a plane curve with the property that the area between any two consecutive full turns around the spiral is invariant. As a result, the distance between turns grows in inverse proportion to their distance from the spiral center, contrasting with the Archimedean spiral (for which this distance is invariant) and the logarithmic spiral (for which the distance between turns is proportional to the distance from the center). Fermat spirals are named after Pierre de Fermat. Their applications include curvature continuous blending of curves, modeling phyllotaxis, plant growth and the shapes of certain spiral galaxy, spiral galaxies, and the design of variable capacitors, solar power reflector arrays, and cyclotrons. Coordinate representation Polar The representation of the Fermat spiral in polar coordinates is given by the equation r=\pm a\sqrt for . The parameter a is a scaling factor affecting the size of the spiral but not its shape. The tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptunea - Links&rechts Gewonden
''Neptunea'' is a genus of large sea snails, marine gastropod mollusks in the subfamily Neptuneinae of the family Buccinidae, the true whelks.Bouchet, P.; Gofas, S. (2010). ''Neptunea'' Röding, 1798. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137710 on 2010-11-02 Species According to the World Register of Marine Species (WoRMS), the following species with valid names are included within the genus ''Neptunea'': *'' Neptunea acutispiralis'' *'' Neptunea alabaster'' *'' Neptunea alexeyevi'' *'' Neptunea amianta'' *'' Neptunea angulata'' *'' Neptunea antarctocostata'' *'' Neptunea antiqua'' *'' Neptunea arthritica'' *'' Neptunea aurigena'' *'' Neptunea behringiana'' *'' Neptunea borealis'' *'' Neptunea bulbacea'' *'' Neptunea communis'' *'' Neptunea constricta'' *'' Neptunea contraria'' *'' Neptunea convexa'' *'' Nep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-similarity
In mathematics, a self-similar object is exactly or approximately similar to a part of itself (i.e., the whole has the same shape as one or more of the parts). Many objects in the real world, such as coastlines, are statistically self-similar: parts of them show the same statistical properties at many scales. Self-similarity is a typical property of fractals. Scale invariance is an exact form of self-similarity where at any magnification there is a smaller piece of the object that is similar to the whole. For instance, a side of the Koch snowflake is both symmetrical and scale-invariant; it can be continually magnified 3x without changing shape. The non-trivial similarity evident in fractals is distinguished by their fine structure, or detail on arbitrarily small scales. As a counterexample, whereas any portion of a straight line may resemble the whole, further detail is not revealed. Peitgen ''et al.'' explain the concept as such: Since mathematically, a fractal may sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Development (differential Geometry)
Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped * Photographic development *Filmmaking, development phase, including finance and budgeting * Development hell, when a project is stuck in development * Development (band), English progressive pop rock band * ''Development'' (album), a 2002 album by Nonpoint Business * Business development, a process of growing a business *Career development * Corporate development, a position in a business * Energy development, activities concentrated on obtaining energy from natural resources *Green development, a real estate concept that considers social and environmental impact of development * Land development, altering the landscape in any number of ways * Land development bank, a kind of bank in India * Leadership development * New product development * Organization development *Professional development *Real estate development *Research and development * Training and de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptical Integral
In integral calculus, an elliptic integral is one of a number of related functions defined as the value of certain integrals, which were first studied by Giulio Fagnano and Leonhard Euler (). Their name originates from their originally arising in connection with the problem of finding the arc length of an ellipse. Modern mathematics defines an "elliptic integral" as any function which can be expressed in the form f(x) = \int_^ R \, dt, where is a rational function of its two arguments, is a polynomial of degree 3 or 4 with no repeated roots, and is a constant. In general, integrals in this form cannot be expressed in terms of elementary functions. Exceptions to this general rule are when has repeated roots, or when contains no odd powers of or if the integral is pseudo-elliptic. However, with the appropriate reduction formula, every elliptic integral can be brought into a form that involves integrals over rational functions and the three Legendre canonical forms, als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Of Integrals
Integration is the basic operation in integral calculus. While differentiation has straightforward rules by which the derivative of a complicated function can be found by differentiating its simpler component functions, integration does not, so tables of known integrals are often useful. This page lists some of the most common antiderivatives. Historical development of integrals A compilation of a list of integrals (Integraltafeln) and techniques of integral calculus was published by the German mathematician (also spelled Meyer Hirsch) in 1810. These tables were republished in the United Kingdom in 1823. More extensive tables were compiled in 1858 by the Dutch mathematician David Bierens de Haan for his '' Tables d'intégrales définies'', supplemented by '' Supplément aux tables d'intégrales définies'' in ca. 1864. A new edition was published in 1867 under the title '' Nouvelles tables d'intégrales définies''. These tables, which contain mainly integrals of elementa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Length
Length is a measure of distance. In the International System of Quantities, length is a quantity with Dimension (physical quantity), dimension distance. In most systems of measurement a Base unit (measurement), base unit for length is chosen, from which all other units are derived. In the International System of Units (SI) system, the base unit for length is the metre. Length is commonly understood to mean the most extended size, dimension of a fixed object. However, this is not always the case and may depend on the position the object is in. Various terms for the length of a fixed object are used, and these include height, which is vertical length or vertical extent, width, breadth, and depth. ''Height'' is used when there is a base from which vertical measurements can be taken. ''Width'' and ''breadth'' usually refer to a shorter dimension than ''length''. ''Depth'' is used for the measure of a third dimension. Length is the measure of one spatial dimension, whereas area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbola
In mathematics, a hyperbola is a type of smooth function, smooth plane curve, curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set. A hyperbola has two pieces, called connected component (topology), connected components or branches, that are mirror images of each other and resemble two infinite bow (weapon), bows. The hyperbola is one of the three kinds of conic section, formed by the intersection of a plane (mathematics), plane and a double cone (geometry), cone. (The other conic sections are the parabola and the ellipse. A circle is a special case of an ellipse.) If the plane intersects both halves of the double cone but does not pass through the apex of the cones, then the conic is a hyperbola. Besides being a conic section, a hyperbola can arise as the locus (mathematics), locus of points whose difference of distances to two fixed focus (geometry), foci is constant, as a curve for each point of which the rays to two fix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
