JEE Main & Advanced Mathematics Complex Numbers and Quadratic Equations Question Bank Relation between roots and coefficients

  • question_answer
    The quadratic in \[t\], such that A.M. of its roots is \[A\] and G.M. is G, is [IIT 1968, 1974]

    A) \[{{t}^{2}}-2At+{{G}^{2}}=0\]

    B) \[{{t}^{2}}-2At-{{G}^{2}}=0\]

    C) \[{{t}^{2}}+2At+{{G}^{2}}=0\]

    D) None of these

    Correct Answer: A

    Solution :

    If \[\alpha ,\beta \] are the roots, then \[A=\frac{\alpha +\beta }{2}\]Þ\[\alpha +\beta =2A\]and\[G=\sqrt{\alpha \beta }\,\,\,\Rightarrow \alpha \beta ={{G}^{2}}\] The required equation is\[{{t}^{2}}-2At+{{G}^{2}}=0\].


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