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Suppose vector u = (-2,3) and vector v = (-5,3) then: (u + v = ?) and (u - v = ?) and (v - u = ?) and (6u = ?) and (-1/8v = ?) and (3u - 4v = ?)

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You have been posting for at least two months, have posted seven questions, and accepted none of the replies you have received. Not very community-minded... –  Arturo Magidin Jan 25 '11 at 5:22
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Before you decide to go ad hominem on another person, please be correct. I have been thankful and happy with many answers I've received. If you have a personal pique against how I word questions or responses, please keep it to yourself unless there's a way to message me personally or you're going to contribute to the community with your response. Other students, who are striving to learn, will ask similar questions. Pertinent responses from other users are ideal. –  Math Student Jan 25 '11 at 5:47
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So why haven't you accepted any of the answers as correct? –  arsmath Jan 25 '11 at 6:52
    
Please see the final paragraph in the faq under How do I ask questions here? "Accepting" an answer is the formal acceptance of the answer you find most helpful in response to your questions. It involves marking the check-mark next to that answer which you find most helpful/useful. You can only accept one answer per question, in case Apostolos reply did not make that clear. Also: "ad hominem" is not a synonym for "personal insult"; it's a very specific kind of rhetorical fallacy. As it happens, I did neither. –  Arturo Magidin Jan 25 '11 at 14:08

2 Answers 2

You add vectors coordinate-wise (coordinate-to-coordinate: the first coordinate of the sum is the sum of the first coordinates of the summands; the second coordinate of the sum is the sum of the second coordinate of the summands, etc). You multiply vectors by scalars coordinate-wise as well (multiply each coordinate by the scalar). You do combinations of vector additions and scalar multiplications by performing the multiplications first and the additions later.

P.S. You are studying for Calculus III and you don't know how to do basic operations with vectors? I confess I find it very hard to believe that this is not contained in your textbook, or was not covered in lecture.

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Thank you for the helpful response. If you want an explanation as to why I'm asking, I do not know how to do this operation yet because the class is beginning. It's what the quiz will be on. We missed the first classes due to weather, as snow is a big deal in my location. I have learned much more on this site or by speaking in person with students and professors in the regards of Mathematics than any textbook. The internet is a great place to learn. –  Math Student Jan 25 '11 at 5:53

This is the most I'll give - http://en.wikipedia.org/wiki/Vector_(geometric)#Vector_addition_and_subtraction - I feel like this question is too homework-y.

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It is homework-esque, I'm doing practice problems for a quiz. It's entirely new material. The answers I'm getting don't seem to be correct. –  Math Student Jan 25 '11 at 5:43

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