Algebra Know-It-ALL

3. Look again at Practice Exercise 3 and its solution from Chap. 27. Create a table of
   values for both functions, based on x-values of −3,−2,−1, 0, 1, 2, 3, and 4. Here are
   the functions that came from the original equations:

y=− 3 x+ 1

476 More Two-by-Two Graphs

AB

C D

E F

Local

max.

Local

min. Local

min.

Local

max.

Figure 28-5 Characteristic shapes for graphs of cubic functions. At A

and B, the curves maintain upward or downward trends,

although they level off at the inflection points (solid dots).

At C and D, the curves maintain upward or downward

trends, and they don’t level off at the inflection points. At

E and F, the curves trend mainly upward or downward but

“back up” between local maxima and local minima, with

inflection points in the “backward zones.”