Question

For the graph x = 78 find the slope of a line that is perpendicular to it and the slope of a line parallel to it. Explain your answer with two or more sentences.

Answer 1

x = 78 is eqn. of line parallel to y-axis as it's x-coordinate is fixed , so line perpendicular to it would be parallel to x-axis which has slope = 0.
& line parallel to it will also be parallel to y-axis having a slope = tan(90°) =<><> (infinity) or undefined ...