Final answer:
To find the equation of a line perpendicular to another, the negative reciprocal of the original slope of the given line is needed. The correct answer is A) Original. Two lines are perpendicular if the product of their slopes is -1.
Step-by-step explanation:
To find the equation of a line perpendicular to another line, you must determine the negative reciprocal of the original slope of the given line. The answer to the fill-in-the-blank question would be 'A) Original.'
A line's slope is a measure of its steepness, and two lines are perpendicular if the product of their slopes is -1. This means if the slope of one line is 'm,' the slope of the line perpendicular to it will be '-1/m,' which is referred to as the negative reciprocal. For example, if the slope of the original line is 2, the slope of the perpendicular line would be -1/2.