# Original document of the Gaussian integral

The Gaussian integral

$$\intop_{-\infty}^{\infty} dx \exp(-x^2) = \sqrt{\pi}$$

is done in a very smart way. But where is the original document?

• Gauss discovered neither the integral nor the "smart way" to evaluate it. – Alexandre Eremenko Nov 4 at 15:10
• You wrote it wrong - you need to indicate the upper and lower bounds. There is no indefinite integral. – Carl Witthoft Nov 5 at 14:00