Leonhard Euler (1707–1783) — The Master of Mathematics Swiss mathematician and physicist whose prolific work shaped nearly every branch of mathematics. 1. Mathematics Euler’s Identity: e^{ipi} 1 = 0 Euler’s Formula for Complex Exponentials: e^{ix} = cos x isin x Euler’s Theorem (Number Theory): Generalization of Fermat’s Little Theorem for coprime integers. Euler–Mascheroni Constant (): Discovered and studied this important constant in analysis. Graph Theory: Solved the Seven Bridges of Königsbe