user manual

Getting Started 9

8300GETM.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 11:06 AM Printed: 02/19/01 11:06

AM Page 9 of 18

Take a 20 cm. × 25 cm. sheet of paper and cut X × X squares from two corners.

Cut X × 12.5 cm. rectangles from the other two corners as shown in the

diagram below. Fold the paper into a box with a lid. What value of X would

give your box the maximum volume V? Use the table and graphs to determine

the solution.

Begin by defining a function that describes the

olume of the box.

From the diagram: 2X + A = 20

2X + 2B = 25

V = A B X

Substituting: V = (20

2X) (25

X) X

1. Press

to display the

editor, which is

where you define functions for tables and

graphing.

2. Press

„

to define the

volume function as

in terms of X.

„

lets you enter

X quickly, without

having to press

. The highlighted

sign indicates that Y

is selected.

Defining a Function: Box with Lid

X B X B