KVPY Sample Paper KVPY Stream-SX Model Paper-30

  • question_answer
    If the tangents at the point P on the circle \[{{x}^{2}}+{{y}^{2}}+6x+6y=2\] meets the straight line \[5x-2y+6=0\] at a point Q on the y axis, then the length of PQ is

    A) 4

    B) \[2\sqrt{5}\]              

    C) 5

    D) \[3\sqrt{5}\]

    Correct Answer: C

    Solution :

    At point \[{{Q}_{1}}\,\,\,x=0\]
    \[\therefore \]in line \[5x-2y+6=0\]
    Put       \[x=0\]  \[\Rightarrow \]   \[y=3\]
    \[\therefore Q(0,3)\]
    \[\therefore PQ=\sqrt{{{0}^{2}}+{{3}^{2}}+6(0)+6(3)-2}=5\]


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