Question

Il

Topic: Parallel and Perpendicular Lines
Which of the following pairs of lines are perpendicular?
Select all that apply.
A. y = 3x + 4 and y Ź x – 8
B.y = x 8 and y= -x –
C. y = x + 2 and y
-x+3
D.y = 3x + 2 and y = 3x - 2
E.y=3 and x = 4
F. y = x 8 and y = -x + 3

Answer 1

Explanation:

If slope of two lines are equal, then they are parallel lines.

If product of the slope of two lines is (-1), then they are perpendicular lines.

C) y = x + 2

Slope m1 = 1

y = -x + 3

Slope m2 = -1

m1 * m2 = 1 * (-1) = -1

These are perpendicular lines.

D) y = 3x + 2

Slope = m1 = 3

y = 3x - 2

Slope = m2 = 3

Slopes are equal. So, they are parallel lines.

E)y= 3

This line is parallel to x -axis.

x = 4

This line is parallel to y-axis.

So, both lines are perpendicular to each other.

F) y = x + 8

slope m1 = 1

y = -x + 3

Slope = m2 = -1

M1 * m2 = 1 * (-1) = -1

So, These are perpendicular lines