Where did Leonhard Euler spend most of his time during the 18th century?

Which mathematician proposed the Goldbach Conjecture in a letter to Euler in 1742?

Who is credited with originating the theory of groups, which became important in 19th and 20th Century mathematics?

Which French mathematician is sometimes referred to as 'the French Newton'?

Who made important contributions to statistics, number theory, abstract algebra and mathematical analysis in the late 18th and early 19th Centuries?

Who was the inventor of descriptive geometry, a method of representing three-dimensional objects by projections on the two-dimensional plane?

Who provided a rigorous proof in 1761 that π is irrational?

Who introduced hyperbolic functions into trigonometry and made some prescient conjectures regarding non-Euclidean space and the properties of hyperbolic triangles?

Who proved that π is also transcendental, i.e. it cannot be the root of any polynomial equation with rational coefficients?