HP 15c - Manual (Page 140)

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
-1
B is
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
Denotes matrix C, row 1, column
1.
-11.2887
Value of c
11
(x
1
).
l C 8.2496
Value of c
21
(x
2
).
´ U 8.2496
Deactivates User mode.
´>0 8.2496
Clears all matrices.
The solution to the system of equations is x
1
= -11.2887 and x
2
= 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.