Question

Select the correct answer.

Which equation represents a line that is perpendicular to line MN?
10
M
N
+++
-10 -8 -6
-4
-2
N
02
8
10
-2
-4
-6
--8
--10
A y =
B.
= -x + 9
y = x + 6
c. y = – 42 - 7
Dy = 40 - 6

Answer 1

D). Y = 4x -6

Explanation:

Let's get the gradient of line MN

Gradient= (y2-y1)/(x2-x1)

Gradient=( 6-3)/(-7-5)

Gradient= 3/-12

Gradient= -1/4

For a line to be perpendicular to line MN , it gradient multiplied with line MN gradient will be equal to -1

MM'= -1

M = gradient of line MN

M' = gradient of the unknown line

MM'= -1

-1/4M'= -1

M' =( -1*4)/-1

M' = 4

So the line will have a gradient of 4

That is, the equation well be in the form of

Y= 4x +c

Where c can be a positive or negative intercept or constant.

The correct option is

D). Y = 4x -6