Bernoulli distribution

The Bernoulli distribution is a discrete probability distribution for a random variable which takes the value 1 with probability pp and the value 0 with probability q=1pq = 1 - p.

f(k;p)=pk(1p)1k for k{0,1}f(k;p) = p^k(1-p)^{1-k} \text{ for } k \in \{0,1\}

Which is basiically, at k=1 (success) probability is pp and at k=0(failure) probability is 1p1-p.

Mean

The mean of the Bernoulli distribution is pp.

Simple proof: E[X]=k=01kf(k;p)=0(1p)+1(1p=p)=pE[X] = \sum_{k=0}^{1} k \cdot f(k;p) = 0 \cdot (1-p) + 1 \cdot (1 \cdot p = p) = p

Variance

The variance of the Bernoulli distribution is p(1p)p(1-p).

Simple proof: E[X2]=k=01k2f(k;p)=02(1p)+12p=pE[X^2] = \sum_{k=0}^{1} k^2 \cdot f(k;p) = 0^2 \cdot (1-p) + 1^2 \cdot p = p

Var[X]=E[X2]E[X]2=pp2=p(1p)Var[X] = E[X^2] - E[X]^2 = p - p^2 = p(1-p)

Bivariate Gaussian distribution

Have to add the formulae and the properties of the bivariate gaussian distribution
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