$$e^{i\pi}+1=0$$

Leonhard Euler (1748)

$$1+\frac{1}{2^2}+\frac{1}{3^2}+\cdots= \frac{{\pi}^2}{6}$$

Leonhard Euler (1735)

$$\int_{-\infty}^{+\infty} e^{-x^2} dx = \sqrt{\pi}$$

$$i \hbar \frac{\partial}{\partial t}\Psi(\mathbf{r},t) = \hat H \Psi(\mathbf{r},t)$$

Erwin Schröndinger (1926)