nonempty set and the collection of all the second coordinates forms another nonempty set.

Activity 1:

Suppose you are given the following relations.
S= {(a, 1), (a, 2), (a, 3), (a, 4)
T= {(x, y) ly=x+1 where r is an integer between 0 and 5}

1. What is the set of all the first coordinates in each relation?
Set S =
Set T =

2. What is the set of all the second coordinates in each relation?
Set S=
Set T= ​