Question

What is the slope of a line perpendicular to x - 3y = 9?
@agent0smith

Answer 1

Is it m = -3

Answer 2

what's the slope of x - 3y = 9 ?

Answer 3

ya its -3. its the reciprocal of the original slope

Answer 4

First get it into slope-intercept form.

x - 3y = 9
subtract x from both sides
-3y = -x + 9
divide both sides by -3
\[\large y = \frac{ x }{ 3 } -3\]
so this slope is 1/3. The perpendicular line will have the negative reciprocal slope... flip the fraction and change the sign.

Answer 5

oh thank you!