Answer:
Undefined
Step-by-step explanation:
The slope on the graph is horizontal so there's no slope and the answer is just y = 3
For a line to be perpendicular to a horizontal line, it is going to be a vertical line.
All vertical lines have an undefined slope.
Answer:
rate of change = 3
Step-by-step explanation:
to find the rate of change 
(0,-4) (1,-1)
=
= 3