• Thumbnail for Projective harmonic conjugate
    In projective geometry, the harmonic conjugate point of a point on the real projective line with respect to two other points is defined by the following...
    16 KB (2,611 words) - 10:07, 13 February 2025
  • include "harmonic" include: Projective harmonic conjugate Cross-ratio Harmonic analysis Harmonic conjugate Harmonic form Harmonic function Harmonic mean Harmonic...
    1 KB (155 words) - 22:09, 14 December 2022
  • parallelogram with d at the fourth vertex. In projective geometry, the process of finding a projective harmonic conjugate is a ternary operation on three points...
    6 KB (708 words) - 23:40, 3 February 2025
  • Thumbnail for Karl Georg Christian von Staudt
    throws (German: Wurftheorie). It is based on projective range and the relation of projective harmonic conjugates. Through operations of addition of points...
    12 KB (1,614 words) - 01:56, 3 March 2025
  • Thumbnail for Complete quadrangle
    Complete quadrangle (category Projective geometry)
    at projective harmonic conjugate positions. The four points on the line deriving from the sides and diagonals of the quadrangle are called a harmonic range...
    8 KB (942 words) - 05:57, 2 April 2025
  • Thumbnail for Cross-ratio
    construction of the projective harmonic conjugate, which he called a throw (German: Wurf): given three points on a line, the harmonic conjugate is a fourth point...
    30 KB (4,844 words) - 22:03, 13 May 2025
  • Under the projective transformations, the incidence structure and the relation of projective harmonic conjugates are preserved. A projective range is the...
    38 KB (5,099 words) - 13:20, 23 January 2025
  • Thumbnail for Projectively extended real line
    the construction of the projective harmonic conjugate relation between points is part of the structure of the real projective line. For instance, given...
    20 KB (3,064 words) - 16:51, 10 August 2023
  • Thumbnail for Midpoint
    affine definition of the midpoint M of a segment AB is the projective harmonic conjugate of the point at infinity, P, of the line AB. That is, the point...
    11 KB (1,415 words) - 07:36, 15 March 2025
  • Thumbnail for Projective line over a ring
    mathematics, the projective line over a ring is an extension of the concept of projective line over a field. Given a ring A (with 1), the projective line P1(A)...
    25 KB (2,979 words) - 04:53, 21 March 2025
  • duality and beyond that to duality in any finite-dimensional projective geometry. A projective plane C may be defined axiomatically as an incidence structure...
    47 KB (5,688 words) - 02:41, 24 March 2025
  • relation of projective harmonic conjugates. Indeed, three points on a projective line determine a fourth by this relation. Application of a projectivity to this...
    3 KB (391 words) - 02:24, 10 October 2022
  • Thumbnail for Jean-Victor Poncelet
    contribution to Feuerbach's theorem. He also made discoveries about projective harmonic conjugates; relating these to the poles and polar lines associated with...
    16 KB (1,602 words) - 22:59, 20 December 2024
  • Thumbnail for Golden spiral
    belonging to arguments θ, θ + π, θ + 2π, θ + 3π the point C is the projective harmonic conjugate of B with respect to A, D, i.e. the cross ratio (A,D;B,C) has...
    12 KB (1,373 words) - 18:03, 20 February 2025
  • Thumbnail for Real projective line
    In geometry, a real projective line is a projective line over the real numbers. It is an extension of the usual concept of a line that has been historically...
    12 KB (1,670 words) - 02:32, 1 December 2024
  • Thumbnail for Conic section
    is the projective harmonic conjugate of the point of intersection of AB and the absolute line, with respect to A and B. A conic in a projective plane that...
    69 KB (9,174 words) - 09:13, 17 May 2025
  • Thumbnail for Power of a point
    pairs M 1 , M 2 ; E , I {\displaystyle M_{1},M_{2};E,I} are projective harmonic conjugate: Their cross ratio is ( M 1 , M 2 ; E , I ) = − 1 {\displaystyle...
    19 KB (3,478 words) - 18:20, 15 February 2025
  • Thumbnail for Poncelet–Steiner theorem
    prescribed circle center. This construction is a special case of the projective harmonic conjugate construction, which is not demonstrated in this article. If...
    92 KB (12,837 words) - 01:04, 16 May 2025
  • Hodge theory (redirect from Harmonic form)
    complex projective manifold, meaning that X is a closed complex submanifold of some complex projective space CPN. By Chow's theorem, complex projective manifolds...
    28 KB (4,339 words) - 19:04, 13 April 2025
  • Thumbnail for Unit hyperbola
    interpreted in the projective plane using homogeneous coordinates. Then the asymptotes are lines that are tangent to the projective curve at a point at...
    10 KB (1,507 words) - 07:45, 24 April 2025
  • Thumbnail for Pole and polar
    Pole and polar (category Projective geometry)
    line were advanced in projective geometry. For instance, the polar line can be viewed as the set of projective harmonic conjugates of a given point, the...
    13 KB (1,358 words) - 15:10, 28 March 2025
  • Thumbnail for Ferdinand Joachimsthal
    "Joachimsthal's Notations". See "Conics and Joachimthal's equation" in Projective harmonic conjugate  This article incorporates text from a publication now in the...
    2 KB (201 words) - 05:47, 28 March 2025
  • Point-pair separation (category Projective geometry)
    each other. Given any pair of points on a projective line, they separate a third point from its harmonic conjugate. A pair of lines in a pencil separates...
    5 KB (601 words) - 02:00, 2 March 2025
  • Thumbnail for Schwarz triangle
    corresponds to the process of inversion in projective geometry and taking the projective harmonic conjugate, which can be defined in terms of the cross...
    78 KB (10,933 words) - 23:50, 14 April 2025
  • use of a third parallel midway between the others that is the projective harmonic conjugate of a line at infinity. In a triangle ABC the feet of the altitudes...
    6 KB (671 words) - 11:27, 18 July 2024
  • Thumbnail for Centre (geometry)
    concept of centre in projective geometry uses this relation. The following assertions are from G. B. Halsted. The harmonic conjugate of a point at infinity...
    7 KB (923 words) - 23:26, 15 May 2025
  • Möbius transformation (category Projective geometry)
    transformations are the projective transformations of the complex projective line. They form a group called the Möbius group, which is the projective linear group...
    70 KB (10,603 words) - 05:07, 10 April 2025
  • Thumbnail for Galois geometry
    axioms for projective n-space, among other things, he considered the consequences of having a fourth harmonic point be equal to its conjugate. This leads...
    10 KB (1,454 words) - 11:02, 9 October 2024
  • Thumbnail for Pappus of Alexandria
    Pappus manipulated the complete quadrangle, used the relation of projective harmonic conjugates, and displayed an awareness of cross-ratios of points and lines...
    24 KB (2,983 words) - 04:53, 4 May 2025
  • (Baker 1922b, vol 2, p. 26) 4.  For harmonic conjugate see harmonic. connex A correspondence between a projective space and its dual. consecutive Infinitesimally...
    81 KB (11,193 words) - 03:00, 26 December 2024