Sponsor Area

Three Dimensional Geometry

Question
CBSEENMA12036160

If the straight lines fraction numerator straight x minus 1 over denominator straight k end fraction space equals fraction numerator straight y minus 2 over denominator 2 end fraction space equals space fraction numerator straight z minus 3 over denominator 3 end fraction space and space fraction numerator straight x minus 2 over denominator 3 end fraction space equals space fraction numerator straight y minus 3 over denominator straight k end fraction space equals fraction numerator straight z minus 1 over denominator 2 end fraction intersect at a point, then the integer k is equal to

  • -5

  • 2

  • 5

  • -5

Solution

A.

-5

fraction numerator straight x minus 1 over denominator straight k end fraction space equals space fraction numerator straight y minus 2 over denominator 2 end fraction space equals space fraction numerator straight z minus 3 over denominator 3 end fraction space and space fraction numerator straight x minus 2 over denominator 3 end fraction space equals space fraction numerator straight y minus 3 over denominator straight k end fraction space equals space fraction numerator straight z minus 1 over denominator 2 end fraction
Since space lines space intersect space in space straight a space point
open vertical bar table row straight k 2 3 row 3 straight k 2 row 1 1 cell negative 2 end cell end table close vertical bar space equals space 0
∴ 2k2 + 5k − 25 = 0
k = − 5, 5/2

Some More Questions From Three Dimensional Geometry Chapter

Find the direction cosines of x, y and z-axis.