Let R be a relation on set N of natural numbers defined by R = {(a, b) : a, b ∊ N, a + 3b = 12} (or a R b : a + 3b = 12).
Find (i) R in Roster form (ii) Domain of R (iii) Range of R.
R = {(x + 1), (x + 5) : x = 0, 1, 2, 3, 4, 5}
= {(a, b) : x = 0, 1, 2, 3, 4, 5}
When x = 0, a = 0 + 1 = 1, b = 0 + 5 = 5
x = 1, a = 1 + 1 = 2, b = 1 + 5 = 6
x = 2, a = 2 + 1= 3, b = 2 + 5 = 7
x = 3, a = 3 + 1 = 4, b = 3 + 5 =8
x = 4, a = 4 + 1 = 5, b = 4 + 5 = 9
x = 5, a = 5 + 1 =6, b = 5 + 5 = 10
Hence, R in the roster form is
{(1, 5), (2, 6), (3, 7), (4, 8), (5, 9), (6, 10)}
Domain of R = {1, 2, 3, 4, 5, 6}
Range of R = {5, 6, 7, 8, 9, 10}
Let R be the relation on Z defined by R = {(a,b): a, b ∈ Z, a – b is an integer}. Find the domain and range of R.
Write the relation : R {(2x+1, x2 -1) : x is an odd prime number less than 10} in Roster form.
Let A = {a, b} and B = {1, 2}. How many relations are three from set A into set B? write all the relations.