Question

Find the angle between the given vectors to the nearest tenth of a degree.

u = <2, -4>, v = <3, -8>

3.0°

6.0°

-7.0°

16.0°

Answer 1

You can use the dot product formula

Answer 2

Or the cross product formula as well if you like

Answer 3

\[
\cos\theta = \frac{u \cdot v}{\|u\|\|v\|}
\]

Answer 4

@juanjohnguy Show me how to cross product these vectors.

Answer 5

hm...just realized that its only in R 2...not sure if it works in R 2

Answer 6

But I was assuming we could just use the formula magnitude(u cross v) = mag(u) times mag(v) sin(theta)

Answer 7

ok?