JEE Main 2019MathematicsThree Dimensional GeometryEasyMCQ

JEE Main 2019 — Three Dimensional Geometry Question with Solution

JEE Main 2019 (09 Jan Shift 2)

Question

If the lines x=ay+b,z=cy+d and x=a′z+b′,  y=c′  z+d′ are perpendicular, then

Choose an option

Show full solutionCorrect option: B
Correct answer
Baa’+c+c’=0

Step-by-step explanation

Direction Ratios of the first line
i^j^k^1-a00c-1=a i^+j^+ck^ 
Hence, Direction Ratios of the first line are a, 1, c.
For Direction Ratios of the second line
i^j^k^10-a′01-c′=a′i^+c′j^+k^
Hence, Direction Ratios of the 2nd line =a′, c′, 1
Since, both the lines are perpendicular,
a.a′+c′+c=0

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About this question

This is a previous-year question from JEE Main 2019, covering the Three Dimensional Geometry chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.