# Thread: Help finding missing endpoint if E is the midpoint of DF. F(5, 8) , E(4, 3)

1. ## Help finding missing endpoint if E is the midpoint of DF. F(5, 8) , E(4, 3)

Find the coordinated of the missing endpoint if E is the midpoint of DF.
F(5, 8) , E(4, 3)

I have no idea at all and I can't find any examples. Thanks for helping.

2. Originally Posted by Zaza757
Find the coordinated of the missing endpoint if E is the midpoint of DF.
F(5, 8) , E(4, 3)

I have no idea at all and I can't find any examples. Thanks for helping.
I suggest you look up the MIDPOINT FORMULA in your textbook....

The midpoint formula says that the coordinates of the midpoint of a segment are the average of the coordinates of the endpoints of the segment. That is,

the x-coordinate of the midpoint is the average of the x-coordinates of the endpoints, and the y-coordinate of the midpoint is the average of the y-coordinates of the endpoints.

One endpoint of the given segment is (5, 8), and the midpoint has coordinates (3, 4), we can let the other endpoint of the segment be (x, y).

The x-coordinate of the midpoint is the average of the x-coordinates of the endpoints. So, (5 + x)/2 = 3

Multiply both sides of that equation by 2: 2(5 + x)/2 = 2*3
5 + x = 6
x = 1

So the x-coordinate of point D must be 1. Use a similar approach to find the y-coordinate of point D.

I'm quite positive that there are examples in your textbook for problems using the midpoint formula...you would not have homework problems like this one if there were NO examples for you to follow.

3. ## help finding endpoint

The midpoint of EF if M(1,-1) one endpoint is E (-3,2) find the endpoint F. can you help my teacher didn't explain it and I can't find an example

4. Originally Posted by thornworn
The midpoint of EF if M(1,-1) one endpoint is E (-3,2) find the endpoint F. can you help my teacher didn't explain it and I can't find an example
I'm sorry to hear that you are being tested over material that your instructor did not mention and your book does not cover. You may want to have a serious talk with somebody in administration, as this is quite improper.

In the meantime, you may want to investigate something called a "search engine". A search engine is an online website what helps you search for things, such as the Midpoint Formula. For instance, Google finds this lesson very quickly. You can go to Google yourself (here) and search for "Midpoint Formula" yourself to find hundreds, maybe thousands, of more lessons.

Please study at least three lessons online. Then please attempt the exercise. If you get stuck, you can then reply with a clear listing of your thoughts and efforts so far, at which point we can begin to work with you. Thank you!

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