JEE Mains · Maths · STD 11 - 4.2 Quadratic equations and inequations
The number of all possible positive integral values of \(\alpha \) for which the roots of the quadratic equation, \(6x^2 - 11x +\alpha =0\) are rational numbers is
- A \(2\)
- B \(5\)
- C \(3\)
- D \(4\)
Answer & Solution
Correct Answer
(C) \(3\)
Step-by-step Solution
Detailed explanation
\(D\) must be perfect square \( \Rightarrow 121 - 24\alpha = {\lambda ^2}\) \( \Rightarrow \) maximum value of \(\alpha \) is \(5\) \(\alpha = 1 \Rightarrow \lambda \notin I\) \(\alpha = 2 \Rightarrow \lambda \notin I\) \(\alpha = 3 \Rightarrow \lambda \in I\) \(\Rightarrow\)…
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