Question

The slope of a line is 1/3.
What is the slope of a line perpendicular to this line?

Answer 1

Answer: 3

Explanation:
See image

Answer 2

-3

Explanation:

Slopes of a perpendicular line are the opposite reciprocal.

So, the opposite of 1/3 is -1/3.

Then the reciprocal of -1/3 is -3 (since -3 is -3/1).