2.1 Bernoulli
The Bernoulli distribution models a single experiment with a binomial outcome. The Bernoulli distribution is a special case of the binomial distribution where a single trial is conducted \((n = 1)\).
If \(X\) is the result of a trial with two outcomes of probability \(P(X = 1) = \pi\) and \(P(X = 0) = 1 - \pi\), then \(X\) is a random variable with a Bernoulli distribution \(X \sim \mathrm{Bernoulli}(\pi)\)
\[f(X = x) = \pi^x (1 - \pi)^{1 - x}, \hspace{1cm} x \in (0, 1)\]
with \(E(X) = \pi\) and \(Var(X) = \pi(1 - \pi)\).