Underrepresented Mathematician:
Sophie Germain
Presented by:
Katie Neville
Sophie Germain’s Background
 Born in 1776 to a middle class family in Paris, France
 Germain became interested in mathematics when reading an
essay on the legend of Archimedes.
 Legend has it that during the Roman Army invasion,
Archimedes was engrossed in mathematics and did not respond
to the Roman soldier. Archimedes was shot.
 Germain taught herself mathematics by reading texts. She
was also allowed to borrow lecture notes from the École
Polytechnique.
 To hide her female identity, Germain submitted papers and
comments under a pseudonym “Monsieur Le Blanc”
Germain’s work in support of Fermat’s
Last Theorem
 Reminder of Fermat’s Last Theorem:
 If an integer n is greater than 2, then the equation an + bn = cn
has no solutions in non-zero integers a, b, and c.
 For prime exponents less than 100, she showed there could
be no solutions relatively prime to the exponent.
 In addition, she proved the following theorem:
 if x, y, and z are integers, and x5 + y5 = z5 then either x, y, or z
has to be divisible by five
 This prove eliminated possible solutions of Fermat’s Last
Theorem in the case where n = 5.
Contributions to the development of
Number Theory
 Germain became interested in number theory and heard
about Fermat’s Last Theorem, which she worked on for a
number of years.
 Germain focused on specific prime numbers
 prime numbers p such that 2p + 1 is also a prime number.
Ex: 5; because 2 x 5 + 1 = 11, which is also prime
 Germain spent much of her time proving that in the case
where exponent n, in Fermat’s Last Theorem was equal to
one of Germain’s primes, there was no solution.
References
 http://www.agnesscott.edu/lriddle/women/germain.htm
 http://womenshistory.about.com/library/bio/blbio_sophie
_germain.htm
 http://www.pbs.org/wgbh/nova/proof/germain.html
 http://en.wikipedia.org/wiki/Sophie_Germain#Contributi
ons_to_number_theory