
Theodorus of Cyrene was an Greek mathematician of the 5th century BC who was admired by Plato, who mentions him in several sources. Little is known about his accomplishments; however, he is atrributed to proving that the square roots of the integer numbers between 3 and 17 except the square numbers 4, 9 and 16 , i.e. 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15 and 17 are irrational (the case for n = 2 was wellknown before him). Retrieved from "http://en.wikipedia.org/" From Plato's Theaetetus to Gauss's Pentagramma Mirificum: A Fight for Truth (PDF) by Bruce Director

