Minimization

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...

Consider the set $S$ of points $(x, y) \in R^2$ which minimize the real valued function $$ f(x, y)=(x+y-1)^2+(x+y)^2 $$ Which of the following statements is true about the set $S$...