Leonhard Euler ( ;
Swiss Standard German ,
German Standard German ) (15 April 170718 September 1783) was a Swiss
mathematician,
physicist,
astronomer,
logician and
engineer who made important and influential discoveries in many branches of mathematics like
infinitesimal calculus and
graph theory while also making pioneering contributions to several branches such as
topology and
analytic number theory. He also introduced much of the modern mathematical terminology and
notation, particularly for
mathematical analysis, such as the notion of a
mathematical function. He is also known for his work in
mechanics,
fluid dynamics,
optics,
astronomy, and
music theory.