The Gamma pdf for continuous random variable Y takes the form f(y)=\left\{\begin{array}{cll}

\frac{1}{\beta^{\alpha} \Gamma(\alpha)} y^{\alpha-1} e^{-y / \beta} & y>0 \\

\mathbf{0} & y \leq 0

\end{array} \quad \text { for } \alpha, \beta>0\right.