Discussion Forum



1)

If  $X= \left\{4^{n}-3n-1:n\epsilon N\right\}$  and  $Y= \left\{9(n-1):n\epsilon N\right\}$  then $X\cap Y$= 


A) X

B) Y

C) $\phi$

D) {0}

Answer:

Option A

Explanation:

We have , 

   $X= \left\{4^{n}-3n-1:n\epsilon N\right\}$ 

   = {0,9,54,........}

and   $Y= \left\{9(n-1):n\epsilon N\right\}$

      = {0,9,18,27,6,45,54.........}

 $\therefore$    $X\cap Y$=   X