Johannes Kepler (15711630)

 Born in Germany.
 He published one one the first works to consider infinitesimals, a concept which led to the formulation of the differential calculus.
 Mohammed ibn Mûsâ alKhowârizmî (fl. ca. 825 CE)
 Born in Iraq.
 He provided solutions of linear equations and quadratic ones.
 Abu Mahmud Hamid ibn AlKhidr alKhujandi (9401000 CE)
 Born in Tajikistan.
 He may have discovered a sine theorem relative to spherical triangles.
 He proved that the sum of two cubic numbers cannot be a cubic number.
 He wrote a text on obliquity of the elliptic, including the measurements of it.
 Seki Kowa (16421708)
 Born in Japan.
 He independently discovered many of the mathematical innovations of the West.
 He was able to popularize mathematics in Japan.
 E. E. Kummer (18101893)
 Born in Germany.
 He established that the proposition that a number can be resolved into the product of powers of primes in only one way is not true of every complex number.
 He wrote on the transformations of hypergeometric functions.