%%

If the line, $${{x - 3} \over 1} = {{y + 2} \over { - 1}} = {{z + \lambda } \over { - 2}}$$ lies in the plane, 2x−4y+3z=2, then the shortest distance between this line and the line, $${{x - 1} \over {12}} = {y \over 9} = {z \over 4}$$ is :

JEE · Math · previous-year question

  1. A.2
  2. B.1
  3. C.0correct
  4. D.3

Answer

C. 0

Explanation

Point (3, $$-$$ 2, $$-$$ $$\lambda $$) on p line 2x $$-$$ 4y + 3z $$-$$ 2 $$=$$ 0 $$=$$ 6 + 8 $$-$$ 3$$\lambda $$ $$-$$ 2 = 0 $$=$$ 3$$\lambda $$ $$=$$ 12 $$\lambda $$ $$=$$ 4 Now, $${{x - 3} \over 1} = {{y + 2} \over { - 1}} = {{z + 4} \over { - 2}} = {k_1}$$ . . .(i) $${{x - 1} \over {12}} = {y \over 9} = {z \over 4} = {k_2}$$ . . .(ii) Point on equation (i) P (k1 + 3, $$-$$ k1 $$-$$ 2, $$-$$ 2k1 $$-$$ 4) Point on equation (ii) Q(12k2 + 1, 9k2, 4k2) k1 + 3 $$=$$ 12k2 + 1 $$\left| { - {k_1} - 2 = 9{k_2}} \right|$$ $$-$$ 2k1 $$-$$ 4 $$=$$ 4k2 k2 $$=$$ 0 k1 $$=$$ $$-$$ 2 p (1, 0, 0) lie on equation of a line 1 gives shortest distance $$=$$ 0

Practice more JEE questions

Answer thousands more real JEE previous-year questions free, get graded instantly, and climb the global ranked leaderboard.

Practice JEE free →

More JEE Math questions