publication . Preprint . 2015

Other trigonometric proofs of Pythagoras theorem

Luzia, Nuno;
Open Access English
  • Published: 23 Feb 2015
Only very recently a trigonometric proof of the Pythagoras theorem was given by Zimba \cite{1}, many authors thought this was not possible. In this note we give other trigonometric proofs of Pythagoras theorem by establishing, geometrically, the half-angle formula $\cos\theta=1-2\sin^2 \frac{\theta}{2}$.
arXiv: Mathematics::History and Overview
free text keywords: Mathematics - General Mathematics
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[1] J. Zimba, On the Possibility of Trigonometric Proofs of the Pythagorean Theorem, Forum Geometricorum, Volume 9 (2009) 275-278.

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