(Fundamentals on covariance function) This question reviews some fundamental properties of covariance function, which is essential for computing autocovariance function. Show the following properties hold. (a) Cov(X,Y)=Cov(Y,X) (b) Cov(X,X)=Var(X) (c) For any constant a,Cov(aX,Y)=aCov(X,Y) (d) For any constant a,Cov(a+X,Y)=Cov(X,Y) (e) If X and Y are independent, Cov(X,Y)=0 (f) Cov(X,Y)=0 does not imply that X and Y are independent (g) Cov(i=1?n?ai?Xi?,j=1?m?bj?Yj?)=i=1?n?j=1?m?ai?bj?Cov(Xi?,Yj?), where ai?,bj? are constants