JEE 2023 — Mathematics PYQ
JEE | Mathematics | 2023Find the shortest distance between line l1 (passing through (2,6,2) and perpendicular to 2x+y−2z=10) and line l2:2x+1=−3y+4=2z.
Choose the correct answer:
- A.
9
(Correct Answer) - B.
8
- C.
7
- D.
6
9
Explanation
Solution:
-
Equation of line l1:
Since it's perpendicular to the plane, its direction ratios are (2,1,−2).
l1:2x−2=1y−6=−2z−2 -
Shortest Distance (SD) Formula:
Line 1: a1=(2,6,2),b1=(2,1,−2)
Line 2: a2=(−1,−4,0),b2=(2,−3,2)
a2−a1=(−3,−10,−2)b1×b2=i^22amp;j^amp;1amp;−3amp;k^amp;−2amp;2=(−4,−8,−8) -
Calculation:
∣b1×b2∣=(−4)2+(−8)2+(−8)2=16+64+64=12SD=∣b1×b2∣∣(a2−a1)⋅(b1×b2)∣=12∣12+80+16∣=12108=9
Correct Option: (4) 9
Explanation
Solution:
-
Equation of line l1:
Since it's perpendicular to the plane, its direction ratios are (2,1,−2).
l1:2x−2=1y−6=−2z−2 -
Shortest Distance (SD) Formula:
Line 1: a1=(2,6,2),b1=(2,1,−2)
Line 2: a2=(−1,−4,0),b2=(2,−3,2)
a2−a1=(−3,−10,−2)b1×b2=i^22amp;j^amp;1amp;−3amp;k^amp;−2amp;2=(−4,−8,−8) -
Calculation:
∣b1×b2∣=(−4)2+(−8)2+(−8)2=16+64+64=12SD=∣b1×b2∣∣(a2−a1)⋅(b1×b2)∣=12∣12+80+16∣=12108=9
Correct Option: (4) 9

