JEE Main202124 Feb 2021Morning ShiftMathematicsMathematical ReasoningActual
The statement among the following that is a tautology is:
Options
- AA ∨ A ∧ B
- BA ∧ A ∨ B
- CB → A ∧ A → B
- DA ∧ A → B → B
Correct answer
D. A ∧ A → B → B
Step-by-step solution
A ∧ A → B → B = A ∧ ~ A ∨ B → B = A ∧ ~ A ∨ A ∧ B → B = A ∧ B → B = ~ A ∧ B ∨ B = ~ A ∨ ~ B ∨ B = T