Question -
Answer -
(i) R= {a, b): a ∈ N, a < 5, b = 4}
Given,
R= {a, b): a ∈ N, a < 5, b = 4}
Natural numbers less than 5 are 1, 2, 3 and 4
a = {1, 2, 3, 4} and b = {4}
R = {(1, 4), (2, 4), (3, 4), (4, 4)}
So,
Domain of relation R = {1, 2, 3, 4}
Range of relation R = {4}
(ii) S= {a, b): b = |a-1|, a ∈ Z and |a| ≤ 3}
Given,
S= {a, b): b = |a-1|, a ∈ Z and |a| ≤ 3}
Z denotes integer which can be positive as well as negative
Now, |a| ≤ 3 and b = |a-1|
∴ a = {-3, -2, -1, 0, 1, 2, 3}
For, a = -3, -2, -1, 0, 1, 2, 3 we get,
S = {(-3, |-3 – 1|), (-2, |-2 – 1|), (-1, |-1 – 1|), (0, |0 – 1|), (1, |1 – 1|), (2, |2 – 1|), (3, |3 – 1|)}
S = {(-3, |-4|), (-2, |-3|), (-1, |-2|), (0, |-1|), (1, |0|), (2, |1|), (3, |2|)}
S = {(-3, 4), (-2, 3), (-1, 2), (0, 1), (1, 0), (2, 1), (3, 2)}
b = 4, 3, 2, 1, 0, 1, 2
So,
Domain of relation S = {0, -1, -2, -3, 1, 2, 3}
Range of relation S = {0, 1, 2, 3, 4}