Consider the line y=8x-4.

What is the slope of a line parallel to this line?
What is the slope of a line perpendicular to this line?

1 answer

The slope of the line y=8x-4 is 8.

Parallel lines have the same slope, so a line parallel to this line will also have a slope of 8.

Perpendicular lines have slopes that are negative reciprocals of each other. The slope of a line perpendicular to y=8x-4 will be the negative reciprocal of 8, which is -1/8.