Q)Let A= {1,2,3,4...20}.
Define a relation 'R' from A to A by R={(x,y):3x-y30,where x,y belongs to A}.Write R in rooster form and hence find its domain, range and codomain.
Answers
Step-by-step explanation:
A={1,2,3...20}
3x-y=0 , 3x=y
X=1;y=3×1=3
X=2;y=3×2=6
X=3;y=3×3=9
X=4;y= 3×4=12
X=5;y=3×5=15
x=6;y=3×6=18. (as 7×3 is 21 and is greater than 20
we didn't take 7as X)
R={(1,3),(2,6),(3,9),(4,12),(5,15),(6,18)}
domain={1,2,3,4,...20}
codomain={1,2,3,....20}
range ={3,6,9,12,15,18}
It is given that the relation R from A to A is given by R = {(x, y): 3x – y = 0, where x, y ∈ A}.
It means that R = {(x, y) : 3x = y, where x, y ∈ A}
Hence, R = {(1, 3), (2, 6), (3, 9), (4, 12)}
We know that the domain of R is defined as the set of all first elements of the ordered pairs in the given relation.
Hence, the domain of R = {1, 2, 3, 4}
To determine the codomain, we know that the entire set A is the codomain of the relation R.
Therefore, the codomain of R = A = {1, 2, 3,…,14}
As it is known that, the range of R is defined as the set of all second elements in the relation ordered pair.