**HP 42S/DM 42/Free42: Function Table**

**Introduction**

The program FTAB uses the function defined in FX, with variable “X” to generate a 2 column matrix of f(X). The matrix is stored in variable MATS. The program ends with MATS in edit mode, so you see all the points generated. Use the soft key [ → ] to view the entries.

Setting up FX

To set up the function FX, the program needs to be in the following format:

00 {nnn-Byte Prgm}

01 LBL “FX”

02 MVAR “X”

03 f(X) starts here, use RCL “X” for X

…

nn-1 RTN

nn END

**HP 42S Program FTAB**

HP 42S, DM 42, Free42

00 { 99-Byte Prgm }

01▸LBL “FTAB”

02 “X Start:”

03 PROMPT

04 STO 01

05 “X Step:”

06 PROMPT

07 STO 02

08 “# Steps:”

09 PROMPT

10 STO 03

11 1

12 –

13 1ᴇ3

14 ÷

15 STO 04

16 RCL 03

17 2

18 DIM “MATF”

19 INDEX “MATF”

20▸LBL 00

21 RCL 01

22 RCL 04

23 IP

24 RCL× 02

25 +

26 STO “X”

27 STOEL

28 J+

29 XEQ “FX”

30 STOEL

31 J-

32 I+

33 ISG 04

34 GTO 00

35 EDITN “MATF”

36 .END.

**Example**

f(x) = x^2 * e^x

FX:

00 { 18-Byte Prgm }

01▸LBL “FX”

02 MVAR “X”

03 RCL “X”

04 ENTER

05 X↑2

06 X<>Y

07 E↑X

08 ×

09 RTN

10 .END.

Input:

X Start: 0

X Step: 0.1

# Steps: 10

Result Matrix MATS:

MATF= [ 10×2 Matrix ]

1:1= 0.0000

1:2= 0.0000

2:1= 0.1000

2:2= 0.0111

3:1= 0.2000

3:2= 0.0489

4:1= 0.3000

4:2= 0.1215

5:1= 0.4000

5:2= 0.2387

6:1= 0.5000

6:2= 0.4122

7:1= 0.6000

7:2= 0.6560

8:1= 0.7000

8:2= 0.9867

9:1= 0.8000

9:2= 1.4243

10:1= 0.9000

10:2= 1.9923

Matrix (row:column)

Eddie

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