Question

Find the union of the given pairs of set: A={1, 2, 3}, B=Ф

Answer 1

concept : if two sets A and B are given, then union of set A and B is written as $A\cup B$. This is the set of all distinct elements that are in Both A or B. see figure, Venn diagram shown, represents that the $\cup$ of any two sets will give all the members of the two sets together, and not replicating the common member twice.

here given, set A = {1 , 2, 3 } and B = $\emptyset$

now, All the members of both sets together are 1, 2, 3
from rule of union, we don't have to replicate members. So, the members of union of these two sets are 1, 2, 3.
therefore, $A\cup B$={1, 2, 3}

Answer 2

Answer:

A U B = A

Step-by-step explanation:

Given A = { 1 , 2 , 3 }

B = { } = empty set

A U B = { x : x € A or x € B }

= { 1 , 2 , 3 } U { }

= { 1 , 2 , 3 }

= A

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