Question

given two points M and N on the coordinate plane, find the slope of line MN, and state the slope of the line perpendicular to line MN:
M(-9,16) N(-11,16)

Answer 1

slope = delta y / delta x

delta y = 0 hence slope = 0

slope perpendicular has no slope since it is vertical

Answer 2

slope perpendicular has no slope since it is vertical

should be

perpendicular line has no slope since it is vertical

Answer 3

i thought it was zero slope?
as the answer?