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

Let u,v and w be vectors such that u+v+w=0. If |u|=3,|v|=4 and |w|=5, then u.v+v.w+w.u is

A
47
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
-25
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
0.0
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
25
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B -25
Since, u+v+w=0|u+v+w|2=0|u|2+|v|2+|w|2+2(u.v+v.w+w.u)=09+16+25+2(u.v+v.w+w.u)=0u.v+v.w+w.u=25

flag
Suggest Corrections
thumbs-up
13
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Dot Product
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon