## anonymous one year ago Could someone please help me? I'm trying to figure out the problem, but none of the answer choices are what my final answer is coming out to be. Find the angle between the given vectors to the nearest tenth of a degree. u = <2, -4>, v = <3, -8> A. 3.0 Degrees B. 6.0 Degrees C. -7.0 Degrees D. 16.0 Degrees I keep getting around 0.99

1. jim_thompson5910

I'm assuming you computed $\Large \frac{u \cdot v}{|u|*|v|} = 0.9945054529214$ correct?

2. anonymous

Yes

3. jim_thompson5910

Apply the arccosine function to both sides to isolate theta $\Large \cos(\theta) = \frac{u \cdot v}{|u|*|v|}$ $\Large \cos(\theta) = 0.9945054529214$ $\Large \arccos(\cos(\theta)) = \arccos(0.9945054529214)$ $\Large \theta = ???$

4. anonymous

Oh! So the answer would be 6??

5. jim_thompson5910

yeah arccos(0.9945054529214) = 6.00900595749781