Identify this namesake of the identity e raised to the i pi power plus one equals zero, and of the number e.
The substitution named for this mathematician is used to take the integral of the square root of a quadratic expression. The path visiting each edge of a graph is named for this person because he proved that the Seven Bridges of Konigsberg Problem is unsolvable. The characteristic named for this person equals the number of vertices minus edges plus faces, which equals two for any simple polyhedron. Identify this namesake of the identity e raised to the i pi power plus one equals zero, and of the number e.
The substitution named for this mathematician is used to take the integral of the square root of a quadratic expression.
(Leonhard Paul) Euler