Question

What value of a makes u and v orthogonal, if u = and v = ? -8 2 4 8 16

Answer 1

Th dot product of orthogonal vectors, should be zero

Answer 2

orthogonal means 0... usually we use the dot product to figure out whether or not it's orthogonal

Answer 3

you have to plug in those values and use dot product and see if one of your choices produces 0

Answer 4

try 4 = a

Answer 5

ok

Answer 6

I get a 16

Answer 7

or a -8

Answer 8

what about that -2 x 8 ?

Answer 9

a -16

Answer 10

(a-4) (a+4)

Answer 11

ok wait wait wait... dot product = u1v1 +u2v2 where u = <u1,u2> and v= <v1,v2>

Answer 12

dot product < - we're multiplying not adding vectors

Answer 13

let's say if u = <a, -2 > and v= <a, 8> and a =4..
then
u = <4,-2> and v < 4.8> now taking dot product I get
(4)(4)+(-2)(8) = 16-16=0

Answer 14

so a*a and 8*-2

Answer 15

another way, for solving your exercise, is:
using the formula for scalar product, we get:
a^2-16=0

Answer 16

yeah .. do you know the dot product formula?

Answer 17

true but that is not how I learned it.

Answer 18

btw a = 4, -4

Answer 19

I rather have it u dot v = u1v1+u2v2....unvn

Answer 20

even he has it like that
http://tutorial.math.lamar.edu/Classes/CalcII/DotProduct.aspx if let a = 4 and use dot product you will have 0

Answer 21

<4,-2>, <4,8>

Answer 22

yes now use the dot product formula ^^

Answer 23

u dot v = u1v1+u2v2+...unvn
where u = < u1, u2....un> and v =<v1,v2... vn>

Answer 24

=2

Answer 25

whattttttttttt

Answer 26

maybe I am looking at the formula wrong

Answer 27

where is your u1 and v1?

Answer 28

4,4

Answer 29

yes so what is 4 x 4 ?

Answer 30

16

Answer 31

yes
so what is u2 and v2?

Answer 32

-2,8

Answer 33

the answer is 4

Answer 34

I was reading wrong my fault

Answer 35

yes a =4
because 4 x 4 + (-2) x 8 = 16-16=0

Answer 36

yea orthogonal is 0

Answer 37

so yea 4

Answer 38

:(

Answer 39

That is probably why I was adding the vectors

Answer 40

my fault :(

Answer 41

it's ok.. as long as you know that dividing vectors is impossible.