Question

let v=(2,8) and w=(-1,-4). which of the following is true
A. v=-2w
B. The x-component of v is 2
C.V*W=-32
D. V and W are perpendicular

Answer 1

let's check one by one:
A. v = -2w
-2w = -2(-1,-4) = (-2*(-1),-2*(-4)) = (2, 8)

Answer 2

so, v = -2w is True

Answer 3

and b is? how would you do that?

Answer 4

V = (2, 8) is a vector with x-componet 2 and y-component 8

Answer 5

v*w = (2,8)*(-1,-4) = 2*(-1) + 8*(-4) = -2 - 32 = -34

Answer 6

so B is false?

Answer 7

B is true, since v's x-componet is 2

Answer 8

oh okay i see

Answer 9

c is false, v*w = -34 and not -32

Answer 10

as v*w is not equal to zero, v and w are not perpendicular

Answer 11

So only A and B are true, thanks

Answer 12

that's it

Answer 13

Np ;)

Answer 14

I have one more question?:)

Answer 15

sure

Answer 16

evaluate the following expression: -1(5,-1)+2(1,1)

Answer 17

what you have done so far?

Answer 18

multiply the two out side numbers?

Answer 19

show your work, then I see where you are getting wrong (if so)

Answer 20

(-5,1)+(2,2)

Answer 21

that's correct, now just sum component by component

Answer 22

(-3,3)?

Answer 23

You got it!

Answer 24

Thanks:D

Answer 25

No problem ^^