Question

Help with projecting vectors

Answer 1

If v = 3i + j and w = -3i − j, then the projection of v onto w is:

Answer 2

(3*-3)+(1*-1)
-9+-1
-10?

Answer 3

Is the projection of v onto w a scalar or a vector?

Answer 4

it's a vector onto another vector

Answer 5

\[\frac{ -10 }{ ||-3i-j|| }(-3,-1)\]

Answer 6

\[\frac{ -10 }{ \sqrt10 }(-3,-1)\]

Answer 7

@freckles does this look alright so far?

Answer 8

(3, 1)

Answer 9

\[proj_wv=\frac{ v \cdot w}{||w||^2} w\]
checking...
v dot w... let's see you got -10 that seems right
and ||w||=sqrt(10)
and ||w||^2=10
ok so when you said
\[\frac{-10}{\sqrt{10}}<-3,-1> \text{ you meant } \frac{-10}{(\sqrt{10})^2}<-3,-1>\]

yeah you do end up with -1<-3,-1>
which is <3,1>

Answer 10

Yay :D