Can someone please tell me how to do these questions? Thanks a lot.

16 Pts (a) Suppose that S is a subset of a metric space M. Define what it means for S to have the Bolzano-Weierstrass Property. 2 pts Write your solution here Now let S be the unit sphere in R3, that is, S = (x ER' : Ilxll = 1}. Suppose that f : S - R is an unbounded function. (b) Show that there exists a sequence (Xn) in S such that If(Xn) | > n for all n EN. 4 pts Write your solution here