grandes-ecoles 2018 Q11

grandes-ecoles · France · centrale-maths1__pc Not Maths Compute MGF or characteristic function for a named distribution
Deduce that, for any real $\xi$, $\int_{-\infty}^{+\infty} \exp\left(-x^{2}\right) \exp(-\mathrm{i} 2\pi \xi x) \mathrm{d}x = \sqrt{\pi} \exp\left(-\pi^{2} \xi^{2}\right)$.
Deduce that, for any real $\xi$, $\int_{-\infty}^{+\infty} \exp\left(-x^{2}\right) \exp(-\mathrm{i} 2\pi \xi x) \mathrm{d}x = \sqrt{\pi} \exp\left(-\pi^{2} \xi^{2}\right)$.