# Proof of Integral (Gradshteyn & Ryzhik 3.462.1)

The following integral appears in Gradshteyn & Ryzhik (8th ed.) 3.462.1

$$\int_{0}^{\infty}x^{\nu-1}\, e^{-\beta x^{2}-\gamma x} \ \mathrm{d}x=\frac{\Gamma(\nu)}{(2\beta)^{\nu/2}}\, \exp\left\{\frac{\gamma^{2}}{8\beta}\right\}\, D_{-\nu}\left(\frac{\gamma}{\sqrt{2\beta}}\right) \quad\quad [\mathrm{Re} \ \beta>0, \ \ \mathrm{Re} \ \nu>0]$$

where, $D_{\nu}(z)$ is the parabolic cylinder function.

Does anyone know where a proof of this solution exists? I am interested in how this integral can be solved.

$$\int e^{-a^{2}x^{2}+bx} \ \mathrm{d}x=\frac{\sqrt{\pi}}{2a}\,\exp\left(\frac{b^{2}}{4a^{2}}\right)\, \mathrm{erf}\left(ax-\frac{b}{2a}\right)$$