Chapter 2.5, Problem 56E

Learning curve. People assigned to assemble circuit boards for a computer manufacturing company undergo on-the-job training. From past experience, the learning curve for the average employee is given by

$N=40\left(1-e^{-0.12t}\right)$

where $N$ is the number of boards assembled per day after $t$ days of training. Graph this function for $0\le t\le 30$. What is the maximum number of boards an average employee can be expected to produce in $1$ day?