2. Solved Papers
  3. JEE Main & Advanced

JEE Main & Advanced JEE Main Paper (Held On 09-Jan-2019 Evening)

  • question_answer
                  The number of all possible positive integral values of a for which the roots of the quadratic equation, \[6{{x}^{2}}-11x+\alpha =0\] are rational numbers is: [JEE Main Online Paper (Held On 09-Jan-2019 Evening]

    A) 4                                             

    B)               2    

    C)               5                                             

    D)               3

    Correct Answer: D

    Solution :

    For rational D must be perfect square \[D=121-24\alpha \] for \[121-24\alpha \] to be perfect square a must be \[3,\text{ }4,\text{ }5\] So, ans \[a=3\] For rational D must be perfect square \[D=121-24\alpha \] for \[121-24\alpha \] to be perfect square a must be \[3,\text{ }4,\text{ }5\] So, ans \[a=3\]


You need to login to perform this action.
You will be redirected in 3 sec spinner