Row Rank Equals Column Rank

  title={Row Rank Equals Column Rank},
  author={William P. Wardlaw},
  journal={Mathematics Magazine},
  pages={316 - 318}
  • W. Wardlaw
  • Published 1 October 2005
  • Geology
  • Mathematics Magazine
1 Hence a butterfly inscribed in a quadrilateral satisfies the same relation (1) as a butterfly inscribed in a circle. Equivalently, the conclusion of the theorem indicates that the ratio of the ratios, (AM/IM)/(CN/IN), is the same as the ratio IA/IC, or that the harmonic mean of IC and IM equals the harmonic mean of IA and IN. In either case, if IC = IA, we have IM = IN thereby the analog of the usual butterfly theorem for quadrilaterals. 

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