The history of continued fractions is certainly one of the longest among
those of mathematical concepts, since it begins with Euclid's algorithm
for the great- est common divisor at least three centuries B.C. As it is
often the case and like Monsieur Jourdain in Moliere's "Ie bourgeois
gentilhomme" (who was speak- ing in prose though he did not know he was
doing so), continued fractions were used for many centuries before their
real discovery. The history of continued fractions and Pade approximants
is also quite im- portant, since they played a leading role in the
development of some branches of mathematics. For example, they were the
basis for the proof of the tran- scendence of 11' in 1882, an open
problem for more than two thousand years, and also for our modern
spectral theory of operators. Actually they still are of great interest
in many fields of pure and applied mathematics and in numerical
analysis, where they provide computer approximations to special
functions and are connected to some convergence acceleration methods.
Con- tinued fractions are also used in number theory, computer science,
automata, electronics, etc ...