Question

Evaluate the expression.

r = <9, -7, -1>, v = <2, 2, -2>, w = <-5, -2, 6>

v ⋅ w

A) <-18, 14, -2>
B) -26
C) 1
D) <-10, -4, -12>

Answer 1

In general if
u = <a,b,c>
v = <d,e,f>
then
u dot v = a*d + b*e + c*f = dot product of the two vectors
In words: multiply the x coordinates together, then the y together and then z together. Finally add up those three products

So,
v dot w = <2,2,-2> dot <-5,-2,6>
v dot w = 2*(-5) + 2*(-2) + (-2)*6
v dot w = -10 - 4 - 12
v dot w = -26

Answer: B) -26

Answer 2

the above person lied and used bots for 5 star ratings the real answer is 6.
Evaluate the expression.

r = <9, -7, -1>, v = <2, 2, -2>, w = <-5, -2, 6>

v ⋅ r (3 points)

<18, -14, 2>

You Answered -26

1

Correct Answer 6