HP HP-15C, Руководство пользователя

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Section 12: Calculating with Matrices 139
Keystrokes Display
| "
8 Deactivates Complex
mode.
2
v ´ m A 2.0000
Dimensions matrix A
to be 2×2.
´ >
1
2.0000
Prepares for automatic
entry of matrix
elements in User mode.
´ U 2.0000
(Turns on the
USER
annunciator.)
3.8
O A A 1,1
Denotes matrix A , row
1, column 1. (A display
like this appears
momentarily as you
enter each element and
remains as long as you
hold the letter key.)
3.8000
Stores a
11
.
7.2
O A
7.2000
Stores a
12
.
1.3
O A
1.3000
Stores a
21
.
.9
“ O A
-0.9000
Stores a
22
.
2
v
1
´ m
B
1.0000
Dimensions matrix B to
be 2×l.
16.5
O B 16.5000
Stores b
11
.
22.1
“ O B -22.1000
Stores b
21
.
´ < C -22.1000
Designates matrix C
for storing the result.
Using matrix notation, the solution of the matrix equation AX = B is
X = A
-1
B
where A
–1
is the inverse of matrix A . You can perform this operation by
entering the ―descriptors‖ for matrices
B and A into the Y- and X-registers
and then pressing
÷
. (A descriptor shows the name and dimensions of a
matrix.) Note that if A and B were numbers, you could calculate the answer
in a similar manner.