Distribution
Beta
p(x) = $\frac{x^{\alpha-1} (1-x)^{\beta-1}}{B(\alpha, \beta)}$
$B(\alpha, \beta)$
Chi Square Distribution
$ Q \sim \chi^2(k) = \sum_{i=1}^{k} Z_i^2 $.
$Z$ is standard normal $k$ is degree of freedom.
Mean = $k$. Variance = $2k$.