La Derivada del Coseno
General Mathematics
2007-05-23 v2
Abstract
The simplest rigourous, non-circular proof that d(cos x) = -sen x. Some details omitted if the gap is intuitive, nevertheles, each gap is easily filled, rigourously. As Ehrenpreis and others have pointed out, the usual text book `proof' is circular, since it assumes the area of circular sectors is already known. Various Cours d'Analyse tomes (Hermite, Jordan, etc.) have correct proofs which, however, are more difficult.
Cite
@article{arxiv.math/0703239,
title = {La Derivada del Coseno},
author = {Joseph F. Johnson},
journal= {arXiv preprint arXiv:math/0703239},
year = {2007}
}
Comments
One page, two figures