How do I solve the following?

Use the vectors u = <2, 2>, v = <-3, 4> and w = <1, -2> to find the indicated quantity.
a) 3u ∙ v

b) (u ∙ 2v)w

1 Answer
Feb 16, 2018

The solution is given below ;-

Explanation:

a) 3vecu.vecv = 3(2hati + 2hatj).(-3hati + 4hatj)

rArr 3vecu.vecv = 3(-6 + 8) = 6

b) (vecu.2vecv)vecw = 2(vecu.vecv)vecw =

2{(2hati+2hatj).(-3hati + 4hatj)}(hati-2hatj)

rArr(vecu.2vecv)vecw = 4(hati-2hatj) = 4hati-8hatj