Solns-Homework4.pdf - MATH 3333 Solutions Homework...

MATH 3333
Solutions: Homework Assignment #4
1. Determine whether the given set is open, closed, or neither open nor closed.
(a) S = ( - 1 , 2) ∪ [3 , ∞ ) Neither
(b) S = ( -∞ , 1) ∪ (2 , ∞ ) Open: every point of
(d) S =
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0 ,
1
2
,
2
3
,
3
4
, · · · ,
n - 1
n
, · · ·
bracerightbigg
∪ [1 , 4]