Show complete solution, thanks.

Subject: Advanced calculus

(9) Show that the given collection F is an open cover for S such that it does not contain a finite subcover and so S is not compact. ((a) S = (0,2); and F = ( U,, | n E N ) where Un = (4.2-4) (b) S = (0,co); and F = ( Un | n E N } where Un = (0,n)