Posts: 52

Threads: 12

Joined: Jul 2007

Lisa.

The section in the manual for Calculating With Matrices is about 41 pages. If you e-mail your address to me, I would send you a reprint.

For now, I will get you started with an example from the manual.

The 15c can work with up to 5 matrices which are named A through E using the 15's corresponding A through E keys. You can specify the size of each matrix, store and recall values of matrix elements and perform matrix operations with complex and real elements. Consider the example.

3.8x1 + 7.2x2 = 16.5

1.3x1 - 0.9x2 = -22.1 determine the values of x1 and x2.

Keystrokes:

g CF 8 deactivates complex mode.

2 Enter f DIM A dimensions matrix A to be 2X2

f Matrix 1 prepares for automatic entry of matrix elements in user mode.

f USER turns on user annunciator

3.8 STO A Denotes Matrix A row 1 column 1

7.2 STO A

1.3 STO A

.9 CHS STO A

2 ENTER 1 f DIM B Dimensions matrix B to be 2X1

16.5 STO B

22.1 CHS STO B

f RESULT C designates matrix C storing the result.

RCL MATRIX B

RCL MATRIX A

/ press divide key

RCL C displays 1, 1 (row 1, column 1)

-11.2887 (value of (X1))

RCL C 8.2496 (value of (X2))

f USER deactivates user mode

f MATRIX 0 Clears all matrices.

The solution to the system is X1 = -11.2887 ans X2 = 8.2496.

Up to 64 matrix elements can be stored in memory. Use all 64 in one matrix or distribute them among up to 5 matrices. Matrix inversion can be performed on an 8X8 with real elements or a 4X4 with complex elements.

If you have need of further help, I suggest you e-mail me directly at wldrylie@702com.net. I will help more. Or e-mail mailing address, I will send you 15C reprint of matrix section of manual. Good luck. I still have fun using my 15C at work. I can also provide many an engineering example from my daily work and programs. Let me know.

Bill.

Posts: 1

Threads: 0

Joined: Jan 1970

I have an out-of-production HP15C, but I have misplaced the basic user's manual, although I have the advanced manual. There is an annoying "c" indicator on the lower level of the window and slightly more than three-quaters to the right. I have a guess as to think that it indicates "complex" mode. But when I when I hit the "Re><Im" button, nothing happens to the "c." Can someone help me? Thanks.