# Recognise probability distribution [duplicate]

Given a PDF, can Mathematica tell me the name of a distribution? The obvious

ProbabilityDistribution[Exp[-x], {x, 0, ∞}]


does not evaluate usefully.

What I'm really interested in is

ProbabilityDistribution[(2 x)/(1 + x^2)^2, {x, 0, ∞}]


which is the ratio of two RayleighDistribution variables?

If I know the name for a distribution, an Internet search may reveal some relevant properties of the distribution.

• Jun 18, 2018 at 21:02