harmonic index
121Partial 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… …
122Perturbation theory — This article describes perturbation theory as a general mathematical method. For perturbation theory as applied to quantum mechanics, see perturbation theory (quantum mechanics). Perturbation theory comprises mathematical methods that are used to …
123Euler–Mascheroni constant — Euler s constant redirects here. For the base of the natural logarithm, e ≈ 2.718..., see e (mathematical constant). The area of the blue region is equal to the Euler–Mascheroni constant. List of numbers – Irrational and suspected irrational… …
124Music of the United States — American music redirects here. For other uses, see American music (disambiguation). Music of United States of America Timeline General topics Education · History G …
125Hooke's law — models the properties of springs for small changes in length Prof. Walter Lewin explains Hooke s law, in …
126Cross-ratio — D is the harmonic conjugate of C with respect to A and B In geometry, the cross ratio, also called double ratio and anharmonic ratio, is a special number associated with an ordered quadruple of collinear points, particularly points on a… …
127Harmonices Mundi — (Latin: The Harmony of the Worlds , 1619) is a book by Johannes Kepler. In the work Kepler discusses harmony and congruence in geometrical forms and physical phenomena. The final section of the work relates his discovery of the so called Third… …
128Maya script — Maya Type Logographic (used both logograms and syllabic characters) Languages Mayan languages Time period 3rd century BCE to …
