Trident Help

Natural Scientific 991 manual · Chapter 14 of 18

Function tables

Build a table of values of f(x) over a range.

14.1Make a table of values#

Press MENU then 9. A form asks for f(x), Start, End and Step. Type the function with ALPHAx) for x and press =. The start, end and step already show 1, 5 and 1; press = to accept or type new values. The table holds up to 45 rows.

Example 14.1

Squares from 1 to 5

  1. Open Table, type x², and accept the range.

    MENU9ALPHAx)x²====
Result of the example "Squares from 1 to 5" The display shows: x | f(x) / 1 | 1 / 2 | 4 / 3 | 9 / 4 | 16 / 5 | 25 / 1.
You should see1 4 9 16 25
Example 14.2

A table in half steps

  1. f(x) = x, start 0, end 2, step 0.5.

    MENU9ALPHAx)=0=2=0.5=
Result of the example "A table in half steps" The display shows: x | f(x) / 0 | 0 / 0.5 | 0.5 / 1 | 1 / 1.5 | 1.5 / 2 | 2 / 0.
You should see1.5

Use ▲ and ▼ to move through the rows; the value of f(x) for the selected row shows at the bottom. Press AC to go back to the form and change the function or range.

Example 14.3

Read a selected row

  1. Squares table, then go down two rows.

    MENU9ALPHAx)x²====▼▼
Result of the example "Read a selected row" The display shows: x | f(x) / 1 | 1 / 2 | 4 / 3 | 9 / 4 | 16 / 5 | 25 / 9.
You should see9
Example 14.4

Back to the setup form

  1. Press AC from the table.

    MENU9ALPHAx)x²====AC
Result of the example "Back to the setup form" The display shows: f(x)=x² / Start=1 / End=5 / Step=1.
You should seef(x)=x² Start=1 End=5 Step=1
The table setup form The display shows: f(x)= / Start=1 / End=5 / Step=1.
The table setup form

14.2When the table does not appear#

  • A step of 0, or an end value that is before the start with a positive step, gives a Math ERROR.
  • More than 45 rows gives a Memory ERROR; widen the step or shorten the range.
  • A row where the function is not defined (for example 1÷x at 0) shows ERROR for that row only.
Example 14.5

Too many rows

  1. Step 1 from 1 to 500.

    MENU9ALPHAx)=1=500=1=
Result of the example "Too many rows" The display shows: Memory ERROR / [AC] :Cancel / [◀][▶]:Goto.
You should seeMemory ERROR

fx-991EX ClassWiz is a trademark of Casio Computer Co., Ltd.. Trident Calculator is an independent product by South View Studios and is not affiliated with, sponsored by or endorsed by Casio. The name is used only to describe the kind of calculator this model resembles; Trident's names, keys, display, fonts and software are its own clean-room design.