Question

For the graph x = -3 find the slope of a line that is perpendicular to it.

a.) -3
b.) -1/3
c.) 0
d.) undefined

Answer 1

When given a line x = "some number", this is a vertical line. No matter what the y value is the x is always -3. A vertical line has undefined slope (or no slope). The line that's perpendicular is a horizontal line. A horizontal line has zero slope - -the x changes, the y does not.

Thus, a line a perpendicular to x = -3 has zero slope. (choice "C")