JEE Main 2018MathematicsThree Dimensional GeometryMediumMCQ

JEE Main 2018 — Three Dimensional Geometry Question with Solution

JEE Main 2018 (08 Apr)

Question

The length of the projection of the line segment joining the points (5,-1, 4) and (4,-1, 3) on the plane, x+y+z=7 is

Choose an option

Show full solutionCorrect option: A
Correct answer
A23

Step-by-step explanation



DR's of AA' (1, 1, 1), as this will be normal to the plane.

DR's of AB is (1, 0, 1)

⇒cos⁡θ=1×1+1×0+1×112+12+1212+02+12=26=23 ,  also AB=2

Projection A1B1=2.sin⁡θ

=2.1-23

=23 
 

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About this question

This is a previous-year question from JEE Main 2018, 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.