Find the angle between vector v and the positive x-axis (Give the absolute value of the angle found. Round your answer to two decimal places).

Question

anonymous · Answer

The original vector is $$v=3i-9j$$

loser66 · Answer

|dw:1377834127137:dw|

anonymous · Answer

Oh, okay. I think I see where to go next.

loser66 · Answer

good

anonymous · Answer

So I am seeing:
$$\cos (\theta) = \frac{ 9 }{ \sqrt{90}\sqrt{9} }$$

loser66 · Answer

It seems good to me. just one more problem, wonder should we normalize those vectors first? or no need to do that. Ok, no need!! since we cancel out it then.

loser66 · Answer

ok, final decision: take yours. It's good.

loser66 · Answer

I am sorry for my opinions. I took the course 1year ago. Just make sure what I said.

anonymous · Answer

It's okay. Thank you so much for your help!

loser66 · Answer

yw