Question

Given vectors u=(-4,-3) and v=(2,-5), determine (4u * v)u.

Answer 1

I am assuming that is a dot product in the middle?

Answer 2

yes, but with 4u*v

Answer 3

@Ruhmeshalle did you see I found my mistake in your prob?
@ahaiakl that is a scalar multiplication

Answer 4

so all you do is multiply each component of u by 4...

Answer 5

that will make u 4 times longer
then use the dot product, which will give you a number
that number will than multiply u aginan according to your equation

so what is 4u ?

Answer 6

again*

Answer 7

(-16,-12)?

Answer 8

yup
now dot with v....

Answer 9

i got 28

Answer 10

me too

Answer 11

now when we multiply again by u, you don't multiply u by 4 right?

Answer 12

no
we already did the 4...
now you have
(28)u
that is all that is left in your problem, another scalar multiplication.

Answer 13

i got (-112,-84)

Answer 14

thats an option! :)

Answer 15

so did I, hope it's a choice

Answer 16

good
we win !

Answer 17

thanks so much you're a genius haha

Answer 18

practice, practice...
thx