wiz-icon
MyQuestionIcon
MyQuestionIcon
25
You visited us 25 times! Enjoying our articles? Unlock Full Access!
Question

Find the projection of (a+2b) on c where a=2^i2^j+^k,b=^i+2^j2^k and c=2^i^j+4^k

A
821
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
821
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
621
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
621
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 621
Given, a=2^i2^j+^k,b=^i+2^j2^k and c=2^i^j+4^k
We need to find the projection of (a+2b) on c
We know that the projection of (a+2b) on c is given by (a+2b).^c, where ^c is the unit vector of c.
So, we have
^c=c|c|=2^i^j+4^k22+(1)2+42=121(2^i^j+4^k)
Also, (a+2b)=(2^i2^j+^k)+2(^i+2^j2^k)
(a+2b)=4^i+2^j3^k
Hence, projection is given by
(a+2b).^c=(4^i+2^j3^k).(121(2^i^j+4^k))
821221=621

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