Rene Descartes
1596 - 1650
“I Think Therefore
I Am”
“Cogito Ergo Sum”
Descartes said that his thinking proved his
existence.He also argued the existence of God and
said, “God according to his philosophy, created two
classes of substance that make up reality.” One class
was thinking substance (minds), and the other was
extended substances (bodies).
Rene Descartes was a
famous French
mathematician, scientist and
philosopher, who was born
in La Haye in 1596. By 1606
he was studying at the
college Jesuit College of La
Fleche. In 1616 he went to
Germany in the army where
he dreamed of finding a
Universal science.
Throughout his lifetime,
Descartes confronted
many scientists and
mathematicians that
everything isn’t based on
probability, he claimed
that certainty is the only
basis of knowledge.
•Compendium Musicae ( attempted to work out a
theory of harmony)
•Discours de la Methode ( discourse the method)
•Regulae ad directionem Ingenii ( Rules for the
direction of the mind)
•Dioptrique ( The Optics)
•Meteors ( meteorology)
•Le Monde( The World)
•Traite de L’homme (treaties on man)
f(x) = xn + an-1 xn-1 + … + a1x + a0
1.) The number of positive real zeros of f is either
equal to the number of variations in sign of f(x) or
less than that number by an even integer.
2.) The number of negative real zeros of f is either
equal to the number of variations in sign of f(-x) or
less than that number by an even integer.
Descartes
made this
chart to
show exact
time.
The Cartesian plane,
named after the Rene
Descartes, is a plane
with a rectangular
coordinate system that
associates each point
in the plane with a pair
of numbers.
Throuhgout his life, Descartes attempted to apply the
rational inductive methods of science and mathematics, to
philosophy. Before his time, philosophy had been based on
comparing and contrasting the views of recognized authorities.
Descartes stated, "In our search for the direct road to truth, we
should busy ourselves with no object about which we cannot
attain a certitude equal to that of the demonstration of
arithmetic and geometry." In mathematics, the most notable
contribution that Descartes made was the systematization of
analytic geometry. He was the first mathematician to attempt to
classify curves according to the types of equations that produce
them. He also made contributions to the theory of equations.
Descartes was the first to use the last letters of the alphabet to
designate unknown quantities and the first letters to designate
known ones. He also invented the method of indices to express
the powers of numbers. Also, he formulated the rule, which is
known as Descartes's rule of signs, for finding the number of
positive and negative roots for any algebraic equation. In
conclusion, Descartes contributed a lot to modern sciences and
mathematics.