梯度、泰勒与Hesse
\[ f(\mathrm{x}) = \sum_{p=0}^{+\infty}\frac{(\mathrm{x} \cdot \nabla)^p}{p!} f(\mathrm{0}) \]
大二生的梦想
Sophomore's dream
所谓 Sophomore's dream,是指如下恒等式:
\[ \int_0^1 x^{-x} \mathrm dx = \sum_{n=1}^\infty n^{-n} \]
CmsMartin
\[ f(\mathrm{x}) = \sum_{p=0}^{+\infty}\frac{(\mathrm{x} \cdot \nabla)^p}{p!} f(\mathrm{0}) \]