Question

If vector {u} = <-5,-5,5>, vector {v} =<0,-1,1>, and vector {w} =<4,-1,2>.
Then what is the answer to this operation?
((vector {w} dot vector {w}) vector {u} ) dot vector {u} =

Answer 1

youre just going to have to run the dots ....

Answer 2

u v and w are find names for vectors .. no need to keep stating that they are vectors each time

Answer 3

in general

k(a,b) . j(x,y) = kajx + kbjy = kj (ax+by)

Answer 4

You lost me cause usually a dot product of one vector onto itself is ||w||^2 which in this case I calculated as sqrt(21). And then you would multiply that result by the u twice. This is my understanding of the problem. But I just can't get the right final answer.

Answer 5

Why did you take the square root of 21? That would be ||w|| not ||w||^2 which is what you're trying to calculate.

Answer 6

w.w is a scalar

u.uis a scalar

(w.w)u . u = w.w * u.u

Answer 7

when we dot a vector to itself: a short cut is simply square the entries, and add them up

Answer 8

okay. thanks.