Practice Exercises
This is an open-book quiz. You may (and should) refer to the text as you solve these
problems. Don’t hurry! You’ll find worked-out answers in App. C. The solutions in the
appendix may not represent the only way a problem can be figured out. If you think you
can solve a particular problem in a quicker or better way than you see there, by all means
try it!
- Look again at Practice Exercise 1 and its solution from Chap. 27. Create a table for
both functions based on x-values of −3,−2,−3/2,−1,−1/2, 0, 1, and 2. Here are the
functions that came from the original equations:
y=− 3 x+ 1
and
y= 2 x^2 + 1
Use bold numerals to indicate the real solutions, if any exist.
- Plot an approximate graph showing the curves based on the table you created when you
worked out Prob. 1. On the x axis, let each increment represent 1/2 unit. On the y axis,
let each increment represent 3 units. Draw the first function’s graph as a solid line or
curve. Draw the second function’s graph as a dashed line or curve. Plot and label all real
solution points, if any exist.
Practice Exercises 475
x
y
(–2/3,95/27)
Figure 28-4 Graphs of y= 5 x^3 + 3 x^2 +
5 x+ 7 and y= 2 x^3 +x^2 +
2 x+ 5. The first function is
graphed as a solid curve; the
second function is graphed
as a dashed curve. The real-
number solution appears as
the point where the curves
intersect. On the x axis, each
increment is 1/2 unit. On
they axis, each increment is
10 units.
