If a segment has an endpoint at (3, 2) and the midpoint at (-1, 2), what are the coordinates of the other endpoint?
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"Question #04c24"
The distance from the midpoint to the first endpoint is #4#, which means that the other endpoint will be at the exact same distance from the midpoint as the first endpoint. So, four to the left of #(-1,2)# is #(-5,2)#
Coordinates of other endpoint#=-5,2#
Let the first endpoint be #A# and midpoint be #B# and other endpoint be #C#
Distance A to B:-
#:.=sqrt((x_2-x_1)^2+(y_2-y_1)^2)#
#:.=sqrt(((-1)-(3))^2+(2-2)^2)#
#:.=sqrt((-4)^2+0#
#:.=sqrt(16)#
#:.=A to B=#4units#
The segment is a vertical line because the# y# values of
#A and B =2#
Coords of #B=-1,2#
The bearing of the line #B to C##=180^@#
#:.cos 180^@=-1xx4.0=-4# add to# x# coord of #B# then
#:.C#=-5#=x # coord.
#:.sin 180^@=0xx4.0=0# add to# y# coord of #B# then
#:.C#=2#=y# coord.
Coordinates of #C=-5,2#
The coordinates of the midpoint of a line is given by:
#((x_1+x_2)/2,(y_1+y_2)/2)#
Let the coordinates of the unknown end be:
#(x_2 , y_2)#
We know the coordinates of the midpoint are:
#(-1,2)#
So:
#((3+x_2)/2,(2+y_2)/2)#
And:
#(3+x_2)/2=-1=>x_2=-5#
#(2+y_2)/2=2=>y_2=2#
Coordinates:
#(-5,2)#