Chapter 14.2, Problem 46E

Mass transportation ridership Suppose that in a certain city, the number of people N using the mass transportation system is a function of the fare f and the daily cost of downtown parking p, so that $N=N(f,p).$

Interpret each of the following.

(a) $N\left(5,20\right)=65,000 \left(\text{b}\right)\frac{\partial N}{\partial f}\left(5,20\right)=-4000$

(c) $\frac{\partial N}{\partial p}(5,20)=2500$