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Wave equation — Not to be confused with Wave function. The wave equation is an important second order linear partial differential equation for the description of waves – as they occur in physics – such as sound waves, light waves and water waves. It arises in… … Wikipedia
Helmholtz equation — The Helmholtz equation, named for Hermann von Helmholtz, is the elliptic partial differential equation:( abla^2 + k^2) A = 0where abla^2 is the Laplacian, k is a constant, and the unknown function A=A(x, y, z) is defined on n dimensional… … Wikipedia
Equation — This article is about equations in mathematics. For the chemistry term, see chemical equation. The first use of an equals sign, equivalent to 14x+15=71 in modern notation. From The Whetstone of Witte by Robert Recorde (1557). An equation is a… … Wikipedia
Proofs of Fermat's theorem on sums of two squares — Fermat s theorem on sums of two squares asserts that an odd prime number p can be expressed as: p = x^2 + y^2with integer x and y if and only if p is congruent to 1 (mod 4). The statement was announced by Fermat in 1640, but he supplied no proof … Wikipedia
Partial differential equation — A visualisation of a solution to the heat equation on a two dimensional plane In mathematics, partial differential equations (PDE) are a type of differential equation, i.e., a relation involving an unknown function (or functions) of several… … Wikipedia
Quartic equation — In mathematics, a quartic equation is one which can be expressed as a quartic function equalling zero. The general form of a quartic equation is:ax^4+bx^3+cx^2+dx+e=0 ,where a ne; 0.The quartic is the highest order polynomial equation that can be … Wikipedia
Dirac equation — Quantum field theory (Feynman diagram) … Wikipedia
Diophantine equation — In mathematics, a Diophantine equation is an indeterminate polynomial equation that allows the variables to be integers only. Diophantine problems have fewer equations than unknown variables and involve finding integers that work correctly for… … Wikipedia
Debye–Hückel equation — The Debye–Hückel equation and Debye–Hückel limiting law, were derived by Peter Debye and Erich Hückel, who developed a theory with which to calculate activity coefficients of electrolyte solutions.[1] Activities, rather than concentrations, are… … Wikipedia
Ordinary differential equation — In mathematics, an ordinary differential equation (or ODE) is a relation that contains functions of only one independent variable, and one or more of their derivatives with respect to that variable. A simple example is Newton s second law of… … Wikipedia
Stochastic differential equation — A stochastic differential equation (SDE) is a differential equation in which one or more of the terms is a stochastic process, thus resulting in a solution which is itself a stochastic process. SDE are used to model diverse phenomena such as… … Wikipedia
