Help with Precalc Vectors? Medal and fan
v = (-7,8)
Find the magnitude of vector v. Express your answer in radical form
sqrt of 113 is what I got for that.
second part: use the magnitude and the angle of vector v to write it in the form (lvlcostheta, lvl sin theta).

I don't know how to determine the single angle for one vector. Earlier in a different part of the problem, I was asked to find the angle between two vectors, but I don't think you use that here since no second vector is provided. So how would I answer the second part?

Thanks(:

Question

Help with Precalc Vectors? Medal and fan
 v = (-7,8)
Find the magnitude of vector v. Express your answer in radical form
sqrt of 113 is what I got for that.
second part: use the magnitude and the angle of vector v to write it in the form (lvlcostheta, lvl sin theta).

I don't know how to determine the single angle for one vector. Earlier in a different part of the problem, I was asked to find the angle between two vectors, but I don't think you use that here since no second vector is provided. So how would I answer the second part?

Thanks(:

mathmale · Answer

The second part of this question refers to the angle measured counterclockwise from the positive x-axis.  Think of the positive x-axis as your second fector.  Try again to solve this question.

anonymous · Answer

That doesn't really help me any. I need to see like a problem I would set up to solve for the angle for the vector. That would help me the most.

mathmale · Answer

Not too tactful, is it, to say "that doesn't really help me any."

I ask you to graph the given point (-7,8) and the given vector <-7,8>, and then draw in two different angles:  1) the angle from the positive x-axis to the given vector, measured counterclockwise, and 2) the angle from the positive x-axis to the given vector, measured clockwise.

anonymous · Answer

No, I'm being honest. I'm not going to say "oh yeah, I understand that" when I don't and it doesn't help me to solve it since I don't understand your terms or what to do. I need further instruction, otherwise it doesn't help. I was not being rude, offensive or judgmental, I'm simply stating I don't understand that, I need more instruction. Please refrain from being caustic. I would never respond to someone who asked a question like that unless they just wanted answers and didn't put any effort into the work.

anonymous · Answer

I'm assuming you mean like this? That's just a rough sketch.|dw:1403376892987:dw|

mathmale · Answer

|dw:1403376971915:dw|

mathmale · Answer

Please copy my drawing and then indicate the angle from the positive x-axis to the given vector <-7,8>.

anonymous · Answer

You're saying the second vector would be (7,0) then? if it lies flat on the positive x axis?

mathmale · Answer

By "indicate," I mean "draw in."  

Let me add in the vector that "lies flat on the positive x-axis."

mathmale · Answer

|dw:1403377336342:dw|