2. Sample Papers
  3. JEE Main & Advanced

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

  • question_answer
    Let \[z\]  be a complex number satisfying \[\frac{{{n}^{2}}-1}{4}.\]on the argon plane. If the locus of \[z\]is a conic C of area a7i and eccentricity e, then the value of \[|a-e|\] is equal to

    A)  \[\frac{9}{8}\]                                     

    B)  \[\frac{81}{64}\]

    C)  \[\frac{9}{64}\]                                    

    D)  9

    Correct Answer: C

    Solution :

    \[|z{{|}^{2}}\,=9|z-1{{|}^{2}}\] \[{{x}^{2}}+{{y}^{2}}=9[{{(x-1)}^{2}}+{{y}^{2}}]\] \[{{x}^{2}}+{{y}^{2}}\,=9({{x}^{2}}+{{y}^{2}}-2x+1)\] \[8{{x}^{2}}+8{{y}^{2}}-18x+9=0\] \[{{\left( x-\frac{9}{8} \right)}^{2}}+{{y}^{2}}=\frac{9}{64}\] \[\therefore \] Area \[=\frac{9\pi }{64}\] and\[e=0\] \[\therefore \,\,a=\frac{9}{64}\]


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