JEE Main 20231 FebruaryEvening Shift
- Exam
- JEE Main
- Year
- 2023
- Date
- 1 February
- Shift
- Evening Shift
- Subject
- Mathematics
- Chapter
- Mathematical Reasoning
JEE Main 2023 · 1 February · Evening Shift · Mathematics · Mathematical Reasoning
Which of the following statements is a tautology?
Which of the following statements is a tautology?
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
We know,
A \to B ≡ ~ A ∨ B
\left(A\right)p \to \left(p ∧ \left(p \to q\right)\right)≡ \left(~ p\right) ∨ \left(p ∧ \left(~ p ∨ q\right)\right)
≡ ~ p ∨ q
\left(B\right)\left(p ∧ q\right) \to \left(~ p \to q\right)
∨ \left(p ∨ q\right)≡ ~ p ∨ ~ q ∨ \left(p ∨ q\right)
Tautology</p><p>\left(C\right) \left(p ∧ \left(p \to q\right)\right) \to ~ q≡ ~ \left(p ∧ \left(~ p ∨ q\right)\right) ∨ ~ q
∨ ~ q≡ ~ p ∨ ~ q
\left(D\right) ≡ p