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TbbZz
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Homework Statement
Write an equation of the perpendicular bisector of the segment joining the points (7,0) and (1,8).
Homework Equations
Midpoint formula, Perpendicular slope (negative reciprocal of a line is the slope of a line perpendicular to the first line)
The Attempt at a Solution
First I get the slope of the line:
m = (8-0)/(1-7) = 8/-6 = -4/3
Then I take the negative reciprocal of it:
m[perpendicular line] = 3/4
Then I use the midpoint formula between the two given points, to find a point on the perpendicular line.
midpoint = (1+7)/2, (8+0)/2
= (4,4)
so I now have the line y=(3/4)x + b as the line. I plug in 4,4
4 = 3/4(4) + b
I solve b to be 1 (b = 1)
so now I have y = 3/4 (x) + 1 as the line.
I'm supposed to give the answer in standard form, so I do:
m =-A/B = 3/4 to get
A = -3
B = 4
and b = C/B = 1 to get
b = 1 = C/4
so C = 4
So my final answer is -3x + 4y = 4
However the correct answer in the back of the book is -3x + 4y = -4
What am I doing wrong?
Thanks for reading.