Let `A={3,5}a n d\ B={7, 11}dot` Let `R={(a , b): a in A ,\ b in b ,\ a-b` is odd`}` . Show that `R` is an empty relation from A and B.

Explanation

Given`,A={3,5}` ` B={7,11}`

`R=(a,b):a∈A,b∈B,a−b` is odd.

Let B=7,a=3

b−a=4, which is even.

Each element of B is odd & A also has odd elements.

Hence a−b is never be odd, it will always negetive even no.

Hence `R=(a,b)∈ϕ.`