73.9k views
2 votes
Determine the slope of the line that is perpendicular to the equation below.

y=-3x +4
Type your answer as a reduced fraction of necessary, like this 3/4

User Gsx
by
5.7k points

2 Answers

6 votes

When the equation of a line is already in the form
y = mx+q, the slope is the coefficient of x, i.e. m.

So, in your case, the slope is -3.

Given a line with slope m, all perpendicular lines will have slope


-\cfrac{1}{m}

So, all lines perpendicular to a line with slope -3 have slope


-\cfrac{1}{-3} = \cfrac{1}{3}

User Paholg
by
5.1k points
5 votes

Product of Slope of a line and its perpendicular is -1.

Suppose slope of a line is m1 and its perpendicular is m2.


m1 * m2 = -1

The general slope intercept form is given by :


y=mx+b

We are given the equation,


y=-3x+4

Comparing our equation with general slope intercept form , we have

slope (m1) = -3

slope of line perpendicular to it (m2) is given by formula above


m1 * m2 = -1

plugging m1=-3 in this


(-3) * m2 = -1

dividing both sides by -3,

m2 =1/3

So slope of line perpendicular to given line is 1/3.


User Atul Balaji
by
5.7k points
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