Question

let A={1,2,3,4,5},B={2,3,6,7},then the number of elements in (A×B) intersection (B×A) is​

Answer 1

We have to find out  (A × B) ∩ (B × A).

Given that A = {1, 2, 3, 4, 5}  and  B = {2, 3, 6, 7}

We have to use the identities given below:

1.  A ∩ B = B ∩ A

2. (A × B) ∩ (C × D)  =  (A ∩ C) × (B ∩ D)

According to the 2nd identity,

(A × B) ∩ (B × A)  =  (A ∩ B) × (B ∩ A)

According to the 1st identity,

(A ∩ B) × (B ∩ A)  =  (A ∩ B) × (A ∩ B)

Thus,

(A × B) ∩ (B × A)  =  (A ∩ B) × (A ∩ B)

Now we have to find  A ∩ B.

A ∩ B = {2, 3}

So,

    (A ∩ B) × (A ∩ B)

⇒  {2, 3} × {2, 3}

⇒  {(2, 2), (2, 3), (3, 2), (3, 3)}

Hence. (A × B) ∩ (B × A)  has 4 elements.

|(A × B) ∩ (B × A)| = 4

Answer 2

Answer:

p*t* kayo mali yan hindi yan yung hinahanap ko