Question: is the slope of a line perpendicular to the x-axis?
Answer: Explanation: the slope of a line parallel to the x -axis has slope 0 . the slope of a line perpendicular to another will have a slope which is its negative reciprocal. the negative reciprocal of a number is −1 divided by the number (e.g. the negative reciprocal of 2 is −12 , which is −12 ).