Need some assistance with Q11 and Q12.

Q11.

11 46On Let X ~ Uniform(0, 7) and Y = cos(X). Find the PDF of Y.12. _)) Suppose that X33, are independent random variables with E(X,;) = ,u. and Var[X) = 0'2, Where 1' = 11 .. . ,n. Let (a) Find mi). (b) Find Valli)