Probability and Statistics - Random Variables

Let X and Y be two real-valued random variables with E(X) = 1, E(Y) = 2, E(X²) = 4, E(Y²) = 9, and E(XY) = 0.9, where E denotes the expectation operator. The value of $\alpha$ that minimizes E( $(X-\alpha Y)^2$) is _____...

Let X be a discrete random variable that is uniformly distributed over the set {-10, -9, ..., 0,..., 9, 10}. Which of the following random variables is/are uniformly distributed?