JEE Main & Advanced Mathematics Circle and System of Circles Question Bank Chord of contact of tangent, Pole and Polar

  • question_answer
    The equation of the circle having as a diameter, the chord \[x-y-1=0\] of the circle \[2{{x}^{2}}+2{{y}^{2}}-2x-6y-25=0\], is

    A)            \[{{x}^{2}}+{{y}^{2}}-3x-y-\frac{29}{2}=0\]               

    B)            \[2{{x}^{2}}+2{{y}^{2}}+2x-5y-\frac{29}{2}=0\]

    C)            \[2{{x}^{2}}+2{{y}^{2}}-6x-2y-21=0\]

    D)            None of these

    Correct Answer: C

    Solution :

               Required circle is                    \[(2{{x}^{2}}+2{{y}^{2}}-2x-6y-25)+\lambda (x-y-1)=0\]                    Its centre is\[\left( \frac{1-\lambda }{4},\ \frac{3-\lambda }{4} \right)\] lies on line\[x-y-1=0\].                    Hence we get the equation of circle                    \[2{{x}^{2}}+2{{y}^{2}}-6x-2y-21=0\].


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