02-06-2005, 07:18 AM
There has been a lot of messages concerning trig. functions for the HP-12C.
Here is a new math theme for the HP-12C fans:
3x3 MATRIX OPERATIONS FOR THE HP-12C
I wrote this program some times ago. I just wanted to see if it is possible to program any 3x3 matrix operations for the HP-12C.
And it was possible...
This program uses Cramer's rule to solve systems of linear equations with 3 unknowns.
In matrix form AX=B.
PROGRAM LISTING
01 0
02 STO 0
03 RCL 5
04 RCL 9
05 *
06 RCL 6
07 RCL 8
08 *
09 -
10 RCL 1
11 *
12 RCL 4
13 RCL 9
14 *
15 RCL 6
16 RCL 7
17 *
18 -
19 RCL 2
20 *
21 -
22 RCL 4
23 RCL 8
24 *
25 RCL 5
26 RCL 7
27 *
28 -
29 RCL 3
30 *
31 +
32 RCL 0
33 X=0?
34 GTO 41
35 /
36 R/S
37 1
38 CHS
39 STO*0
40 GTO 44
41 RDN
42 STO 0
43 /
44 RCL 1
45 RCL 2
46 RCL 3
47 RCL n
48 STO 3
49 RDN
50 STO 2
51 RDN
52 STO 1
53 RDN
54 STO n
55 RCL 4
56 RCL 5
57 RCL 6
58 RCL i
59 STO 6
60 RDN
61 STO 5
62 RDN
63 STO 4
64 RDN
65 STO i
66 RCL 7
67 RCL 8
68 RCL 9
69 RCL PV
70 STO 9
71 RDN
72 STO 8
73 RDN
74 STO 7
75 RDN
76 STO PV
77 GTO 03
USER INSTRUCTIONS
1) Key in the program
2) Store elements of matrix A into registers R1 through R9
3) Store elements of matrix B into registers n, i and PV
4) Press [f] [PRGM] [R/S] to calculate x1
5) Press [R/S] to calculate x2
6) Press [R/S] to calculate x3
7) Press [R/S] once again to return elements of matrices A and B into their original registers (-1.00 will be displayed)
8) For a new case, go to step 2 or 3.
Rem: If Det A=0, then the system is linearly dependent and this program is not applicable (Error 0 will be displayed)
Ref: For example HP-34C Mathematics Applications Book