If the Boolean expression is a tautology, then and are respectively by:
- (A)→ , →✓ Correct
- (B)
- (C)
- (D)
Answer: (A)
Solution
Take both connectives to be the implication, giving . If is true, then and are both true, so is true and the whole statement is true; if is false, an implication with a false antecedent is true. The statement holds in all four rows of the truth table, so it is a tautology.
No other pairing works: and are both false when is false, and is false when is true and is false.
So and are both the implication .
No other pairing works: and are both false when is false, and is false when is true and is false.
So and are both the implication .
JEE Main · 2021 · 17 Mar 2021 · Shift 2 · Single correct option