Analyzing Graphs with the First Derivative

Learning Objectives

  • Intervals of increasing/decreasing
  • Local extrema
  • Applications

Exercises

1.

\(f(x)\) is increasing on \((-\infty,4).\)

\(f(x)\) is decreasing on \((4,\infty).\)

2.

  1. \(x=-2,0,6\)
  2. \(x=-\sqrt{27},0,\sqrt{27}\)

3.

Critical Values: \(x=1,3\)
\(f\) is increasing on \((-\infty,1)\) and \((3,\infty).\)
\(f\) is decreasing on \((1,3).\)
Local Maximum of 6 at \(x=1.\) 
Local Minimum of 2 at \(x=3.\)

4.

The revenue function is increasing on the interval \((0,140)\) and decreasing on the interval \((140,\infty)\). It has a local maximum of \(\$3920\) when \(x=140\) web cameras are sold.