test latex on blogspot

Method1,
following http://mathcache.appspot.com/static/docs.html
use javascript to render latex
$$ \pi = 4 \sum_{k=1}^{\infty} \frac{(-1)^{k+1}}{2k-1}$$

Method2,
edit on http://www.codecogs.com/components/equationeditor/equationeditor.php
show generated image directly