Testing MathJax

$$ \log\sum_{i=1}^n\exp(f(x_i)) $$ \[ \log\sum_{i=1}^n\exp(f(x_i)) \] And inline: \( \log\sum_{i=1}^n\exp(f(x_i)) \) and $ \log\sum_{i=1}^n\exp(f(x_i)) $