The line perpendicular to the line AB passes through the point
i.e.,
.
Further explanation:
From the given figure in the question it is observed that the line AB passes through the points
and
.
The coordinate for the point C is
.
Step1: Obtain the slope of the line AB.
The slope of a line which passes through the points
and
is calculated as follows:
(1)
It is given that the line AB passes through the points
and
.
To obtain the slope for the line AB substitute
for
,
for
,
for
and
for
in equation (1).
![\begin{aligned}m&=\frac{-8-4}{2+2}\\&=\frac{-12}{4}\\&=-3\end{aligned}](/tpl/images/0421/2207/ee26c.png)
Therefore, the slope of the line AB is
.
Consider the slope of AB as,
so,
.
Step2: Obtain the slope of the perpendicular line.
The slope of line AB is
.
Consider a line which is perpendicular to the line AB passing through the point C. Assume the slope of the perpendicular line as
.
The product of slope of two mutually perpendicular lines is always equal to
.
The equation formed for the slope is as follows:
![\fbox{\begin\\\ \math m_{1}\times m_{2}=-1\\\end{minispace}}](/tpl/images/0421/2207/1f00b.png)
Substitute the value of
in the above equation.
![\begin{aligned}-3\times m_{2}&=-1\\m_{2}&=\frac{1}{3}\end{aligned}](/tpl/images/0421/2207/ed0e6.png)
Therefore, the slope of the perpendicular line is
.
Step3: Obtain the equation of the perpendicular line.
The slope for perpendicular line is
and the line passes through the point C. The coordinate for the point C are
.
The point slope form of a line is as follows:
![\fbox{\begin\\\ \math (y-y_{1})=m(x-x_{1})\\\end{minispace}}](/tpl/images/0421/2207/298a3.png)
Substitute
for
,
for
and
for
in the above equation.
![\begin{aligned}(y-4)&=\frac{1}{3}(x-6)\\3y-12&=x-6\\3y-x&=6\end{aligned}](/tpl/images/0421/2207/d72c0.png)
Therefore, the equation of the perpendicular line is
.
Option 1:
In option 1 it is given that the line perpendicular to AB passes through the point
.
The equation of the line which is perpendicular to AB is
.
Substitute
for
in the above equation.
![\begin{aligned}3y-(-6)&=6\\3y+12&=6\\3y&=-6\\y&=-2\end{aligned}](/tpl/images/0421/2207/d28b7.png)
From the above calculation it is concluded that the line passes through the point
.
This implies that option 1 is incorrect.
Option 2:
In option 2 it is given that the line perpendicular to AB passes through the point
.
The equation of the line which is perpendicular to AB is
.
Substitute
for
in the above equation.
![\begin{aligned}3y-(0)&=6\\3y&=6\\y&=2\end{aligned}](/tpl/images/0421/2207/106cc.png)
From the above calculation it is concluded that the line passes through the point
.
This implies that option 2 is incorrect.
Option 3:
In option 3 it is given that the line perpendicular to AB passes through the point
.
The equation of the line which is perpendicular to AB is
.
Substitute
for
in the above equation.
![\begin{aligned}3y-(0)&=6\\3y&=6\\y&=2\end{aligned}](/tpl/images/0421/2207/106cc.png)
From the above calculation it is concluded that the line passes through the point
.
This implies that option 3 is correct.
Option 4:
In option 4 it is given that the line perpendicular to AB passes through the point
.
The equation of the line which is perpendicular to AB is
.
Substitute
for
in the above equation.
![\begin{aligned}3y-(2)&=6\\3y&=8\\y&=\frac{8}{3}\end{aligned}](/tpl/images/0421/2207/39e0d.png)
From the above calculation it is concluded that the line passes through the point
.
This implies that option 4 is incorrect.
Therefore, the line perpendicular to the line AB passes through the point
i.e.,
.
Learn more:
1.A problem on composite function link
2.A problem to find radius and center of circle link
3.A problem to determine intercepts of a line link
Answer details:
Grade: High school
Subject: Mathematics
Chapter: Lines
Keywords: Geometry, coordinate geometry, lines, equation, graph, curve, slope, perpendicular, point slope form, slope intercept form.