Question

if A={1,2,3,4} ; B={1,2,3,4,5,6,7,8} then find AúB , A intersection B .what do you notice about the result?​

Answer 1

Answer:

A∪B = {1,2,3,4,5,6,7,8}

A∩ B = {1,2,3,4}

A∪B = B

A∩B = A

Step-by-step explanation:

Given:

A={1,2,3,4}

B={1,2,3,4,5,6,7,8}

A∪B:

A∪B = {X:X ∈ A or X ∈ B}

That means, All elements in A and B without repetition.

A∪B = {1,2,3,4} ∪ {1,2,3,4,5,6,7,8}

= {1,2,3,4,5,6,7,8}

{1,2,3,4,5,6,7,8} = B

Therefore, A∪B = B

A∩B:

A∩B= {X:X ∈ A and X∈ B}

That means, Elements common to both A and B.

A∩ B = {1,2,3,4}∩ {1,2,3,4,5,6,7,8}

= {1,2,3,4}

{1,2,3,4} = A

Therefore,

A∩B = A