Casio fx-CG10 Advanced Operation Manual page 69

Chapter 1: Polynomial Functions
Sample Solution—Trends in Nightly Rates for Hotels (continued)
From the graph of average nightly hotel rates of Milwaukee, as a function of
time in years since 2000, it appears as if the rates were increasing in 2000,
but then decreased until 2003. The rates were increasing between 2003 and
2007, and began decreasing again in 2008.
Equation:
To find the relative minima and maxima of these functions using the
symbolism of mathematics would require students to use a first derivative.
This is another example of how the graphing calculator can provide students
access to mathematical concepts using graphs and tables before they have
the knowledge of the symbolic procedures that would be utilized.