Question 4 of 33intermediate🔍 AnalyzeShort Answer2 marks

State whether each of the following statements are true or false. If the statement is false, rewrite the given statement correctly.

(i)

If P={m,n}P = \{m, n\} and Q={n,m}Q = \{n, m\}, then P×Q={(m,n),(n,m)}P \times Q = \{(m, n), (n, m)\}.

Answer

False. Correct statement: If P={m,n}P = \{m, n\} and Q={n,m}Q = \{n, m\}, then P×Q={(m,n),(m,m),(n,n),(n,m)}P \times Q = \{(m, n), (m, m), (n, n), (n, m)\}.

(ii)

If AA and BB are non-empty sets, then A×BA \times B is a non-empty set of ordered pairs (x,y)(x, y) such that x∈Ax \in A and y∈By \in B.

Answer

True.

(iii)

If A={1,2}A = \{1, 2\}, B={3,4}B = \{3, 4\}, then A×(B∩ϕ)=ϕA \times (B \cap \phi) = \phi.

Answer

True.

Explanation

For part (i), the Cartesian product P×QP \times Q involves pairing every element of set PP with every element of set QQ. Since P={m,n}P=\{m, n\} and Q={n,m}Q=\{n, m\}, there are 2×2=42 \times 2 = 4 possible ordered pairs, not just the two listed. For part (ii), the statement correctly defines the Cartesian product for non-empty sets. For part (iii), the intersection of any set BB with the empty set ϕ\phi is ϕ\phi, and the Cartesian product of any set AA with an empty set results in an empty set.