Published by:
CGP EDU Academic Team
Published on: August 11, 2026
The angle between the lines whose direction cosines satisfy the equations l + m + n = 0 and l 2 = m 2 + n 2 is
A
B
C
D
Text Solution
Verified by ExpertsThe correct answer is:
C
...............
...............
⇒ 
– (– – m) 2 = 0
⇒ 2m(m + ) = 0
m = 0 or = – m
so direction ratios are – 1, 0, 1 and – 1, 1, 0
∴ cos θ = 
= 
──────────────────────────────────────────────────────────────────────────────────────────
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
If , , are non-coplanar vectors and p, q are real numbers, then the equality [3 p p ] – [p …
Let the line = = lies in the plane x + 3y – α z + β = 0. Then ( α , β ) equals
The projections of a vector on the three coordinate axes are 6, –3, 2 respectively. The direction c…
Let and . Then the vector satisfying and is
If the vectors , and are mutually orthogonal, then ( λ , µ) =
Statement -1 : The point A(3, 1, 6) is the mirror image of the point B(1, 3, 4) in the plane x – y …