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Consider the vectors bar(a)=hat(i)-2hat(...

Consider the vectors `bar(a)=hat(i)-2hat(j)+hat(k) and bar(b)=4hat(i)-4hat(j)+7hat(k)`.
What is the scalar projection of `bar (a) ` on ` bar( b)` ?

A

1

B

19/9

C

17/9

D

23/9

Text Solution

Verified by Experts

The correct Answer is:
B
Projection of `vec(a) ` on ` vec(b) = (vec(a).vec(b))/(|vec(b)|)=((hat(i)-2hat(j)+hat(k)).(4hat(i)-4hat(j)+7hat(k)))/(|sqrt(4^(2)+(-4)^(2)+7^(2))|)`
`=(19)/(9)`
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