Question

Let v1 = (-6,4) and v2 = (-3, 6). What would be the angle between |v1| and |v2| ?Help is appreciated(:

Answer 1

Have you considered the Inner Product (or Dot product)? It leads to the cosine of the desired angle.

Answer 2

I know the dot product is involved but idk how to use it exactly.

Answer 3

do you know the equation for the dot product?

Answer 4

no

Answer 5

\(\vec{a}.\vec{b} = |\vec{a}||\vec{b}| cos(\theta)\)

Answer 6

<-6, 5> . <-3, 6> = |<-6, 5>| |<-3, 6>| cos(theta)

Answer 7

if your studying 2D vectors that equation should be in your text book?

Answer 8

simplify

Answer 9

over to you now JV

Answer 10

when u knw the components, u can compute the dot product by :-
*multiply the same components
*add them

Answer 11

<-6, 5> . <-3, 6> = |<-6, 5>| |<-3, 6>| cos(theta)
----------------

Answer 12

that becomes : (-6)*(-3) + (5)(6)

Answer 13

(-6)*(-3) + (5)(6) = |<-6, 5>| |<-3, 6>| cos(theta)

see if u can take it from here

Answer 14

okay, thanks I think I can take it from there. But can you also please help on how to find the scalar projection of v1 onto v2? @ganeshie8