How do you find the missing coordinate if P=(4,-1) is the midpoint of the segment AB, where A=(2, 5)?
1 Answer
Jun 15, 2016
Explanation:
Recall that the midpoint formula is:
color(blue)(|bar(ul(color(white)(a/a)M=((x_1+x_2)/2,(y_1+y_2)/2)color(white)(a/a)|)))
In your case:
Let
M=(4,-1)
Let(x_1,y_1)=(2,5)
Let(x_2,y_2)= coordinate of B
Start by plugging your known values into the formula.
(4,-1)=((2+x_2)/2,(5+y_2)/2)
Since you are looking for
4=(2+x_2)/2color(white)(XXXXXXXX)-1=(5+y_2)/2
In each equation, solve for the variable.
8=2+x_2color(white)(XXXXXXXxx)-2=5+y_2
x_2=6color(white)(XXXXXXXXXXXx)y_2=-7
Hence, the coordinate of
B=color(green)(|bar(ul(color(white)(a/a)color(black)(((6,-7)))color(white)(a/a)|)))