Let A = {0, 1, 2, 3, 4, 5, 6, 7, 8} and let R = {(a, b) : a, b ϵ A and 2a + 3b = 12}. Express R as a set of ordered pairs. Show that R is a binary relation on A. Find its domain and range.
Let A = {0, 1, 2, 3, 4, 5, 6, 7, 8} and let R = {(a, b) : a, b ϵ A and 2a + 3b = 12}. Express R as a set of ordered pairs. Show that R is a binary relation on A. Find its domain and range.

 

Answer : A = {0, 1, 2, 3, 4, 5, 6, 7, 8} 2a + 3b = 12

a=0 è b=4 a=3 è b=2 a=6 è b=0

R = {(0, 4), (3, 2), (6, 0)}

Since, R is a subset of A × A, it a relation to A.

The domain of R is the set of first co-ordinates of R Dom(R) = {0, 3, 6}

The range of R is the set of second co-ordinates of R Range(R) = {4, 2, 0}