Question

Line m has a slope of 0. Line n is perpendicular to line m. What is the slope of line n?

Answer 1

Your answer would be A, Line n has an undefined slope.

The slope of a line perpendicular to another is the negative reciprocal of the other line.

In this case, the slope of this line is just 0. It'll be better to think of it as instead of 0, something like 0/1, or 0/2, which are equivalent to 0 but work better with the explanation. I'm just going to use 0/1

Therefore, when you take the negative reciprocal of the slope of 0/1, then you end up with -1/0 as the slope of line n. When you divide by 0, the answer is always undefined. Therefore, the line has an undefined slope.

Another way to think about this is by thinking of Line m as a horizontal line. A line with a slope of 0 is just a horizontal line. Perpendicular lines are lines that meet at 90 degree angles. Therefore, the line that would meet with line m, line n, would be a vertical line. And since vertical lines have an undefined slope, line n would have an undefined slope.

Hope this helped!