JAMIA MILLIA ISLAMIA Jamia Millia Islamia Solved Paper-2013

  • question_answer
        The image (reflection) of the point\[(1,2,-1)\] in the plane\[r.(3i-5j+4k)=5\]is

    A)  \[\left( \frac{73}{25},\frac{-6}{5},\frac{39}{25} \right)\]

    B)  \[\left( \frac{73}{25},\frac{6}{5},\frac{39}{25} \right)\]

    C)  \[(-1,-2,1)\]

    D)  None of the above

    Correct Answer: A

    Solution :

                    Since, the plane is \[3x-5y+4z-5=0.\] If image of point\[(1,2,-1)\]in the plane is\[({{x}_{2}},{{y}_{2}},{{z}_{2}})\]then \[\frac{{{x}_{2}}-1}{3}=\frac{{{y}_{2}}-2}{-5}=\frac{{{z}_{2}}+1}{4}=\frac{-2(3-10-4)}{9+25+16}\] \[\therefore \]  \[({{x}_{2}},{{y}_{2}},{{z}_{2}})=\left( \frac{73}{25},\frac{-6}{5},\frac{39}{25} \right)\]


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