Find the angle between the given vectors to the nearest tenth of a degree. u = , v = ?

Question

Find the angle between the given vectors to the nearest tenth of a degree. u = <6, -1>, v = <7, -4>?

hartnn · Answer

do you know the formula?

kendellfawn · Answer

No idea, this lesson is all over the place, covers a lot. Mind walking me through this?

hartnn · Answer

sure
you may use this one, though there are other ways
$u.v = |u||v|\cos \theta $

kendellfawn · Answer

Okay, so how would I go about setting this up?

hartnn · Answer

you know how to find u.v, right?

hartnn · Answer

|u| is the magnitude of vector u

kendellfawn · Answer

Yes. Okay.

hartnn · Answer

so what do u get for 
|u|
|v|
and
u.v ?

mathmale · Answer

Look up "vector magnitude" or some similar search term.
Given vector u=<6, -1>, how would you find its magnitude?  For reference, this magnitude is $$\sqrt{6^2+1^2)}.$$   Verify that.  Find the magnitude (length) of vector v also.

mathmale · Answer

hartnn was encouraging you to use the dot product of vectors u and v, and he has given you the proper formula for this.  Any questions about "dot product?"