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

^i×(a×^i)+^j×(a×^j)+^k×(a×^k) is always equal to

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

The correct option is C 2a
We have
^i×(a×^i)
=(^i.^i)a(a.^i)^i
=a(a.^i)^i

Similarly,
^j×(a×^j)
=a(a.^j)^j

^k×(a×^k)
=a(a.^k)^k

Now
^i×(a×^i)+^j×(a×^j)+^k×(a×^k)
=3a[(a.^i)^i+(a.^j)^j+(a.^k)^k]=2a

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