Coordinates of Endpoint of a SegmentDate: 11/01/2002 at 16:12:35 From: Rachel Brock Subject: Midpoint Dear Dr. Math, I am completely stuck on this question: Determine the coordinates of the other endpoint of a segment with an endpoint at (1,-1) and a midpoint at (2,5). We have learned the midpoint formula, but have yet to learn anything like this. Thank you for your time! Date: 11/01/2002 at 18:35:43 From: Doctor Ian Subject: Re: Midpoint Hi Rachel, Here's one way to think about it. Suppose you're standing on a big grid at location (1,-1). How would you have to move (how far to the right? how far up?) to get to (2,5)? You could represent it this way: (2,5) = (1+a, -1+b) Now, what if instead, you went to (?,?) = (1+2a, -1+2b) ? In other words, whatever you did to move from (1,-1) to (2,5), you did again, but starting at (2,5)? Wouldn't that make (2,5) the midpoint of (1,-1) and wherever you ended up? Does this help? Write back if you're still confused, or if you have other questions. - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ Date: 11/02/2002 at 13:09:50 From: Rachel Brock Subject: Midpoint Thank you so much for your help. I completely understand it now. |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/