Question

How to start?

Answer 1

just typing and everything out...

Answer 2

u=<2,-1> what are the vector v1 and v2 with norma 5 and 60 degrees with vector u?\]

Answer 3

the norm 5 for which vector? v1 or v2?

Answer 4

yes

Answer 5

ah, I got it, they are only 1, different direction, right?

Answer 6

give me sec.

Answer 7

ok

Answer 8

you have formula to count that
let v =<x,y> you have \[\cos 60 = \frac{ <u,v> }{ |u||v| }\]

Answer 9

and cos 60 = 1/2 , |u| = sqrt(5) ; |v| = 5 so, just count the numerator which is
<(2,-1), (x,y)>

Answer 10

can you step up from here?

Answer 11

thanks!

Answer 12

np

Answer 13

yes I can.

Answer 14

glad to hear that. "Yes!! We can!!!":)

Answer 15

;)