.

To find read this thread: http://www.mathhelpforum.com/math-he...sson-dist.html

Get in a similar way.

You can also get and from themoment generating function. For the derivation of the moment generating function read this thread: http://www.mathhelpforum.com/math-he...tribution.html. If you haven't learnt about the moment generating function then forget I mentioned it.