Question

Need Pre-calc help
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Find the angle between the given vectors to the nearest tenth of a degree.

u = <6, -1>, v = <7, -4>

Answer 1

@zepdrix

Answer 2

We have some kind of handy formula for dealing with this, yes?
\[\Large\rm \cos \theta=\frac{\vec u\cdot \vec v}{||u||~||v||}\]Where theta is the angle between them.

Answer 3

and ||u|| is the magnitude?

Answer 4

\[\Large\rm \cos \theta=\frac{<6, -1>\cdot<7, -4>}{||<6, -1>||~||<7, -4>||}\]Yes :) Length of the vector, magnitude.

Answer 5

can you remind me how to find the magnitude? I'm very rusty at this stuff