140 Section 12: Calculating with Matrices

Keystrokes

Display

 

 

 

l > B b

2

1

Enters descriptor for B, the 2×1

 

 

 

 

constant matrix.

l > A A

2

2

Enters descriptor for A, the 2×2

 

 

 

 

coefficient matrix, into the X-

 

 

 

 

register, moving the descriptor

 

 

 

 

for B into the Y-register.

÷

running

 

Temporary display while A-1Bis

 

 

 

 

being calculated and stored in

 

 

 

 

matrix C.

 

C

2

1

Descriptor for the result matrix,

 

 

 

 

C, a 2×1 matrix.

Now recall the elements of matrix C – the solution to the matrix equation. (Also remove the calculator from User mode and clear all matrices.)

Keystrokes

Display

l C

C 1,1

 

-11.2887

l C

8.2496

´ U

8.2496

´>0

8.2496

Denotes matrix C, row 1, column 1.

Value of c11 (x1).

Value of c21 (x2). Deactivates User mode. Clears all matrices.

The solution to the system of equations is x1 = -11.2887 and x2 = 8.2496.

Note: The description of matrix calculations in this section presumes that you are already familiar with matrix theory and matrix algebra.

Matrix Dimensions

Up to 64 matrix elements can be stored in memory. You can use all 64 elements in one matrix or distribute them among up to five matrices.

Page 140
Image 140
HP 15c Scientific manual Matrix Dimensions, Running, 11.2887, 2496