Thursday, July 30, 2009

Will someone help me with this problem about vectors?

a vector has the following intial terminal points respectively


initial poin (-1 , 2)


terminal point (4 , 6)


what is the position vector


a 3i + 4j


b 5i+4j


c 3i-4j


d 5i-4j

Will someone help me with this problem about vectors?
The j component is 6-2 = 4


and the i component is 4 - (-1) = 5





so the vector form is 5i+4j
Reply:let resultant vector be r


r = 5i + 4j
Reply:I believe position vector is the same as finding components, in which case, this is how you do it : (x2 - x1)i + (y2 - y1)j





If that's the case, then it is simple.





(4 - (-1))i + (6 - 2)j





[After that step you can automatically eliminate choices C and D because they have a negative j.]





5i + 4j





The answer is B.





Again, I'm not 100% sure, but I would answer it this way on a test.





Good luck. I know more about vector word problems than these type of things (I'm not so good with the vocabulary) so if you need any help on vector word problems, feel free to IM me.


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