JEE Main & Advanced Mathematics Three Dimensional Geometry Question Bank Line and Plane

  • question_answer
    The line joining the points (3, 5, ?7) and (?2, 1, 8) meets the yz-plane at point [RPET 2003]

    A)            \[\left( 0,\,\frac{13}{5},\,2 \right)\]

    B)            \[\left( 2,\,0,\,\frac{13}{5} \right)\]

    C)            \[\left( 0,\,2,\,\frac{13}{5} \right)\]

    D)            (2, 2, 0)

    Correct Answer: A

    Solution :

                       Line joining the points (3,5,?7) and (?2,1,8) is, \[\frac{x-3}{(-2)-(3)}=\frac{y-5}{(1)-(5)}=\frac{z-(-7)}{8-(-7)}\]                        \[\frac{x-3}{-5}=\frac{y-5}{-4}=\frac{z+7}{15}=K\], (Let)                          ?..(i)            \ \[x=-5K+3\], \[y=-4K+5\], \[z=15K-7\]            \[\because \]  Line (i) meets the yz-plane                    \[\therefore \] \[-5K+3=0\Rightarrow K=3/5\]            Put the value of K in \[x,\,y,\,z\]            So the required point is (0, 13/5, 2).


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