College Algebra & Trigonometry, 2018a

198 CHAPTER 4. FUNCTIONS
We can use the graphing calculator to find maximum and minimum values. In
calculus the maximum and minimum values can be found algebraically.
The maximum and minimum values are also helpful in determining where the
function is increasing or decreasing. In the previous example:
5
−3 −2 −1
−5
1 2 3 4 5
−10
−15
−20
−25
The function is increasing between x = −2 and x = −1, then again from x =3to
x =4. So we would say that the intervals in which the function is increasing are
−2 ≤ x