Question

Which are the lines below is perpendicular to y = 3x + 4?

A) Y= –3x+ 7
B) Y=-1/3x+2
C) Y= 3x- 5
D) Y=1/3x+1

Answer 1

B

Explanation:

the equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

y = 3x + 4 ← is in slope- intercept form

with slope m = 3

given a line with slope m then the slope of a line perpendicular to it is

`m_(perpendicular)` = -
`(1)/(m)` = -
`(1)/(3)` , then

y = -
`(1)/(3)` x + c ← is the form of a perpendicular line

the only one from the list fitting this description is

y = -
`(1)/(3)` x + 2 ← equation of perpendicular line , that is B