1.Previous
3.Next

:Canceling terms and dividing by Fermat arrived at
:Removing the terms that contained Fermat arrived at the desired result that the maximum occurred when .

Fermat also used his principle to give a mathematical derivation of Snell's laws of refraction directly from the his principle that light takes the quickest path.

Descartes' criticism

Fermat's method was highly criticized by his contemporaries, particularly Descartes.

1.Previous
3.Next