CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Let u and v be the unit vectors such that u×v+u=w and w×u=v. Then the value of [u v w] is equal to

A
1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
0
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 1
Given: u×v+u=w(i) and w×u=v(ii)
Multiplying equation (i) by u
(u×v+u)×u=w×u
(u×v×u)+u×u=v From (ii)
(u×v×u)+0=v
(u.u)v(u.v)u=v
As u is unit vector. So u.u=1
(1)v(u.v)u=v
(u.v)u=0
Hence,
(u.v)=0(iii)
Now, [u v w]
u.(v×w)
u.(v×(u×v+u))
u.(v×(u×v)+v×u)
u.((v.v)u(v.u)v+v×u)
u.((1)u0+v×u)
u.u+u.(v×u)
12+[u v u]
1+0=1



flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon