Question

Are the vectors s=(3, -4) and t=(11, 8) normal?
Please help!

Answer 1

@hartnn

Answer 2

Normal to a plane? or just normal in general?

Answer 3

Just normal in general I guess

Answer 4

Well normal referring to a plane..means a vector perpendicular to the plane...

So we need to see if these 2 vectors are perpendicular to each other...

We can do that by calculating the dot product, and seeing if it = 0

If it is...then we have perpendicular vectors

Answer 5

Do you know how to calculate the dot product of 2 vectors?

Answer 6

I am not sure. Do I just multiply x*x and y*y?

Answer 7

Like 3*11 and -4*8?

Answer 8

Yeah and then add the results.

\[\large <a,b>\cdot <c,d> = (a \times c) + (b \times d)\]

Answer 9

So it equals to 1.

Answer 10

Correct.....and since that isn't 0 ...we find that these are not "normal" "perpendicular" vectors

Answer 11

That's it? That was easy!

Answer 12

Exactly :) lol

Answer 13

Lol thanks for your help! :)

Answer 14

Anytime :)