wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

If a,b,c be three non-coplanar vectors and r be any arbitrary vector, then (a×b)×(r×c)+(b×c)×(r×a)+(c×a)×(r×b) is equal to?

A
0
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
[abc]r
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2[abc]r
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
3[abc]r
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 2[abc]r
We have
(a×b)×(r×c)=((a×b)c)r((a×b)r)c=[abc]r[abr]c
similarly
(b×c)×(r×a)=[bca]r[bcr]a
Similarly
(c×a)×(r×b)=[cab]r[car]b
When we add all three
We get
3[abc]r[abc]r=2[abc]r


flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Application of Vectors - Planes
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon