How do you find the coordinates of the other endpoint of a segment with the given endpoint of a segment is (12, -8) and the midpoint is (3, 18)?

1 Answer
Jun 22, 2016

The other end is at (-6,44)(6,44)

Explanation:

The vector displacement from (12,-8)(12,8) to (3,18)(3,18) is
color(white)("XXX")vec(""(3-12,18-(-8)))= vec(""(-9,26))XXX−−−−−−−−−−−−−−−(312,18(8))=−−−−−−(9,26)

A point twice as far away from (12,8)(12,8) (but through (3,18)(3,18)
would have a vector displacement of
color(white)("XXX")2xxvec(""(-9,26))=vec(""(-18,52))XXX2×−−−−−−(9,26)=−−−−−−−(18,52)
from (12,-8)(12,8)

(12,-8)+vec(""(-18,52))=(-6,44)(12,8)+−−−−−−−(18,52)=(6,44)