midpoint of (-21,-9) and endpoint of (-16,-13). WHat is the other endpoint?

Question

I understand how to perform midpoint and distance formula on the points to get either the midpoint of the distance from points, but I still am I little confused on how to find a missing endpoint.

Answer 1

I am not going to do this problem for you, but I will tell you how to do it.

You must first find the equation of the line joining the 2 given points.

You also need the distance between the two given points.

The endpoint will satisfy the equation of the line and be at an equal distance from the midpoint.

I warn you that the arithmetic is messy!

Answer 2

THe other endpoint is (x,y)

(x+-16)/2 = -21 and (y + -13)/2 = -9

x + -16 = -42 and y + -13 = -18

x = -26 and y = -5

(-26,-5)