Question

Evaluate the expression:

v ⋅ w

Given the vectors:

r = <5, -5, -2>; v = <2, -8, -8>; w = <-2, 6, -5>

Answer 1

Multiply all the corresponding components together, and add up the results.

eg if
v = <5, 3, -2>
and
w = <1, 0, 2>

then v * w = 5*1 + 3*0 + (-2)*2 = 1

Answer 2

@agent0smith so do i do that ^^ but for all 3?

Answer 3

You don't need to. You only need v*w, you can ignore r!

Answer 4

\[v.w=\left( 2 \right)\left( -2 \right)+\left( -8 \right)\left( 6 \right)+\left( -8 \right)\left( -5 \right)\]

Answer 5

@agent0smith may i ask why is r there? i'm sorry this chapter has confused me

Answer 6

v= <2, -8, -8>
w= <-2, 6, 5>

v ⋅ w can be found by following the example above.

Answer 7

r is there because it's there :P

Answer 8

@agent0smith haha thank you ♥

Answer 9

r is just a vector which you do not need. Don't get confused by unnecessary information.

Answer 10

@agent0smith Okay thank you so much c:

Answer 11

@agent0smith so for mine it would be : v*w= (2)(-2)+ (-8)(6)+(-8)(-5)= 12

Answer 12

Yes! :)