Answer:
Undefined
Step-by-step explanation:
You can deduce the solution in two ways: if the slope of m is zero, it is horizontal. So, n is vertical because it must be perpendicular to n. Vertical lines have undefined slope.
Alternatively, if the slope of line m is k, the slope of a perpendicular line n is -1/k. So, if k=0, you can't compute -1/0.
