He solved the problem of the Seven (*) Bridges of Königsberg, thus pioneering graph theory.
This mathematician's name is applied to the totient (TOH- shunt) function, and his eponymous characteristic is the number of vertices minus edges plus faces of a topological space. His identity states that his namesake number to the power of i x equals cosine of x plus sine of ix. This scientist went blind in one eye from a fever and later the other from a cataract. He solved the problem of the Seven (*) Bridges of Königsberg, thus pioneering graph theory. Name this scientist for whom is named the logarithmic base e, a Swiss mathematician.
This mathematician's name is applied to the totient (TOH- shunt) function, and his eponymous characteristic is the number of vertices minus edges plus faces of a topological space.
Leonhard {Euler} (OY-lur)