Expert: Sherman D. - 2/2/2006

Question
"Triangle RES has vertices R(0,0), E (4,-6) and S(8,4). Find the equation of the perpendicular bisector of Segment RE"


This is a question from my math book that I don't understand, can you help me?

Answer
Midpoint of RE
(0,0) and (4,-6)
Mx = (4 + 0)/2 = 4/2 = 2
My = (-6 + 0)/2 = -6/2 = -3
Midpoint = (2,-3)

Using that

(2,-3) and (8,4)
m = (4 - (-3))/(8 - 2)
m = (4 + 3)/6
m = 7/6

m = (7/6), (8,4)
4 = (7/6)(8) + b
4 = (56/6) + b
4 = (28/3) + b
12 = 28 + 3b
3b = -16
b = (-16/3)

ANS : y = (7/6)x - (16/3)

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Proof : Here are the equations to each coordinate, which you can type in at www.calculator.com/calcs/GCalc.html

y = (-3/2)x
y = (1/2)x
y = (5/2)x - 16

Then type in (7/6)x - (16/3) and you will see that the equation will bisect Segment RE.

By the way, you will need Java to use the graph, also make sure to keep out the y = part, because you don't need it, and if you do plug it in, the graphs will not show up. Also the equations must be in y = form. You can also try www.quickmath.com, and click on Plot under Equations, and then click on Advanced, so you can put multiply equations in.