Question: Use the set-roster notation to indicate the elements in each of the following sets.
a. S = {n ∈ Z| n = (-1)k , for some integer k}.
b. T = {m ∈ Z | m = 1 + (-1)i , for some integer i}.
c. U = {r ∈ Z| 2 ≤ r ≤ -2}
d. V = {s ∈ Z| s > 2 or s
e. W = {t ∈ Z | 1
f. X = {u ∈ Z | u ≤ 4 or u ≥ 1}