2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main Sample Paper-21

  • question_answer
    If \[\alpha \] and \[\beta \] are the roots of the quadratic equation \[p{{x}^{2}}+qx+r=0\]where \[\alpha \beta =99\] and p, q, r (taken in that order) are in arithmetic progression, then \[(\alpha +\beta )\] equals

    A)  100                             

    B)  - 100

    C)  50                               

    D)  - 50

    Correct Answer: D

    Solution :

    \[\alpha +\beta \,=\frac{-q}{p};\,\,\alpha \beta \,=\frac{r}{p}\] Also \[2q=p+r\] \[\therefore \,\frac{2q}{p}=1+\frac{r}{p}\] \[-2(\alpha +\beta )\,=\alpha \beta \,=1+99=100\] \[\Rightarrow \,(\alpha +\beta )\,=-50\]


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