A line segment is bisected by a line with the equation 4 y - 2 x = 3 . If one end of the line segment is at ( 5 , 6 ), where is the other end?

1 Answer
Jun 16, 2018

The other end of the line segment is at (7.2,1.6)

Explanation:

First of all, the bisector of a line segment is perpendicular to the segment.

Perpendicular slope is the negative reciprocal of the original slope, so first step is to find the slope of the given line.

Step 1: Finding the equation of the line segment

Convert to slope-intercept form y=mx+b

4y-2x=3
4y = 2x+3
y=2/4x+3/4
color(red)(m=2/4)

Taking the negative reciprocal we have the slope of our line segment color(red)(m=-4/2)

NOTE: Because the bisector intersects the line segment at the midpoint, we can use the given point to find our b value.

6=-4/2(5)+b
6=-20/2+b
6+10=b
color(red)(b=16)

This gives us the equation of the line segment on infinite domain y=-4/2x+16

Step 2: Equate the two lines to find the intersection point at x

2/4x+3/4=-4/2x+16

Group x values together and factor

x(2/4+4/2)=-3/4+16
x(2/4+8/4)=-3/4+64/4

(10x)/4=61/4

10x=61

color(red)(x=6.1)

Sub in 6.1 to either equation to find y.

y=-4/2(6.1)+16
y=-24.4/2+16
y=-12.2+16
y=3.8

So our intersection point is at (6.1,3.8)

Step 3: Find the endpoint using the midpoint formula

Because the intersection point (6.1,3.8) is also a midpoint, we can find the final point using the midpoint formula.

((x_1+x_2)/2, (y_1+y_2)/2)

Substitute the original points at x_1,y_1

(5+x_2)/2=6.1
x_2=6.1(2)-5
x_2=7.2

(6+y_2)/2=3.8
y_2=3.8(2)-6
y_2=1.6

Answer

(x,y)=(7.2,1.6)

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