In general, how does one separate the product of two probability distributions with one of them known? Basically, I have the distribution of rcosθ, I know that P(cosθ) = 2/(πsinθ), and I want to find P(r). Wolfram Alpha makes me think that a delta function is involved based on what they say about uniform product distributions and normal product distributions, but I wouldn't know how to solve it in this case. Here are the URLs to Wolfram Alpha's things. I can't include links until I make 10 posts apparently. mathworld.wolfram.com/UniformProductDistribution.html mathworld.wolfram.com/NormalProductDistribution.html Thanks for any help or suggestions!