Published by:
CGP EDU Academic Team
Published on: August 14, 2026
The straight lines whose direction cosines are given by 
and 
are perpendicular to each other, then the value of 
is equal to
Text Solution
Verified by ExpertsThe correct answer is:
B
We have,
From Eq. (i),
Put the value of 
in Eq. (ii), we get
or 
Let 
Let two values of 
be 
and 
.
Product of roots 
Now, lines are perpendicular, if
Hence, 
──────────────────────────────────────────────────────────────────────────────────────────
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
PHYSICS
SINGLE CORRECT MCQ
A stone is thrown vertically up from the top of a tower which reaches th…
Two massive bodies of masses and are at rest and separated by infinite distance. Now, they move t…
Assertion The net dipole moment of a given volume containing large number of polar molecules is zer…
A boy is in a lift which is moving downwards with an acceleration . At an instant when the velocit…
Statement I If the centre of mass of a system is at rest, the KE of the system must be zero.
Statem…
Two resistances are expressed as and . The equivalent resistance of their series and parallel com…