Hi, I was hoping that someone might be able to please help me with this proof.
Prove that var(x+y) ≤ 2(var(x) + var(y)).
So far I have:
var(x+y) = var(x) + var(y) + 2cov(x,y)
where the cov(x,y) = E(xy) - E(x)E(y), but I'm not really sure to go from there.
Any insight would be very...