Let X and Y be i.i.d. Unif(0,1) and let W=X-Y. (a) Find the mean and variance of W, without yet deriving the PDF (b) Show that the distribution of W is symmetric about 0, without yet deriving the PDF. (c) Find the PDF of W. (d) Use the PDF of W to verify your results from (a) and (b) (e) How does the distribution of W relate to the distribution of W relate to the distribution of X+Y, the triangle distribution.