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If A = {1, 3, 5) B = {3, 4} and C = {2, 3}, verify that: (i) A × (B ∪ C) = (A × B) ∪ (A × C) (ii) A × (B ∩ C) = (A × B) ∩ (A × C) |
Answer» (i) Given: A = {1, 3, 5}, B = {3, 4} and C = {2, 3} L. H. S = A × (B ⋃ C) By the definition of the union of two sets, (B ⋃ C) = {2, 3, 4} = {1, 3, 5} × {2, 3, 4} Now, by the definition of the Cartesian product, Given two non – empty sets P and Q. The Cartesian product P × Q is the set of all ordered pairs of elements from P and Q, .i.e. P × Q = {(p, q) : p Є P, q Є Q} = {(1, 2), (1, 3), (1, 4), (3, 2), (3, 3), (3, 4), (5, 2), (5, 3), (5, 4)} R. H. S = (A × B) ⋃ (A × C) Now, A × B = {1, 3, 5} × {3, 4} = {(1, 3), (1, 4), (3, 3), (3, 4), (5, 3), (5, 4)} and A × C = {1, 3, 5} × {2, 3} = {(1, 2), (1, 3), (3, 2), (3, 3), (5, 2), (5, 3)} Now, we have to find (A × B) ⋃ (A × C) So, by the definition of the union of two sets, (A × B) ⋃ (A × C) = {(1, 2), (1, 3), (1, 4), (3, 2), (3, 3), (3, 4), (5, 2), (5, 3), (5, 4)} = L. H. S ∴ L. H. S = R. H. S is verified (ii) Given: A = {1, 3, 5}, B = {3, 4} and C = {2, 3} L. H. S = A × (B ⋂ C) By the definition of the intersection of two sets, (B ⋂ C) = {3} = {1, 3, 5} × {3} Now, by the definition of the Cartesian product, Given two non – empty sets P and Q. The Cartesian product P × Q is the set of all ordered pairs of elements from P and Q, .i.e. P × Q = {(p, q) : p Є P, q Є Q} = {(1, 3), (3, 3), (5, 3)} R. H. S = (A × B) ⋂ (A × C) Now, A × B = {1, 3, 5} × {3, 4} = {(1, 3), (1, 4), (3, 3), (3, 4), (5, 3), (5, 4)} and A × C = {1, 3, 5} × {2, 3} = {(1, 2), (1, 3), (3, 2), (3, 3), (5, 2), (5, 3)} Now, we have to find (A × B) ⋂ (A × C) So, by the definition of the intersection of two sets, (A × B) ⋂ (A × C) = {(1, 3), (3, 3), (5, 3)} = L. H. S ∴ L. H. S = R. H. S is verified |
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