CLASS-8
DIFFERENCE BETWEEN TWO SETS

DIFFERENCE OF TWO SET

Let A & B be any two sets, then the difference of A & B is the set of elements which belongs to A but not to B and this is denoted by A – B

We can write  A – B = { x : x A and x B }

Similarly,      B A = { x : x B and x A }

Example.1)

Let A = { 2, 4, 6, 8 }, and B = { 1, 2, 3, 4, 5 } then find A B = ? and  B A = ?

Ans.) as per the given condition A = { 2, 4, 6, 8 }, and B = { 1, 2, 3, 4, 5 }

So, A B = { 2, 4, 6, 8 } - { 1, 2, 3, 4, 5 }

( As we know that, the elements which belong to A but not to B are the difference between A – B )

  A B = { 2, 4, 6, 8 } - { 1, 2, 3, 4, 5 } = { 6, 8 }

And with same condition like A = { 2, 4, 6, 8 } and B = { 1, 2, 3, 4, 5 }, we have to find B A

So, B A = { 1, 2, 3, 4, 5 } - { 2, 4, 6, 8 }

( As we know that, the elements which belong to B but not to A are the difference between B – A )

  B A = { 1, 2, 3, 4, 5 } - { 2, 4, 6, 8 }  =  { 1, 3, 5 }