HP HP-15C

Section 12: Calculating with Matrices 145
Keystrokes
Display
´ > 1
Sets beginning row and column
numbers in R
0
and R
1
to 1.
(Display shows the previous
result.)
´ U
Activates User mode.
1 O A
A 1,1
Row 1, column 1 of A.
(Displayed momentarily while
A key held down.)
1.0000
Value of a
11
.
2 O A
2.0000
Value of a
12
.
3 O A
3.0000
Value of a
13
.
4 O A
4.0000
Value of a
21
.
5 O A
5.0000
Value of a
22
.
6 O A
6.0000
Value of a
23
.
lA
A 1,1
Recalls element in row 1,
column l. (R
0
and R
1
were reset
in preceding step.)
1.0000
Value of a
11
.
l A
2.0000
Value of a
12
.
l A
3.0000
Value of a
13
.
l A
4.0000
Value of a
21
.
l A
5.0000
Value of a
22
.
l A
6.0000
Value of a
23
.
´ U
6.0000
Deactivates User mode.
Checking and Changing Matrix Elements Individually
The calculator provides two ways to check (recall) and change (store) the
value of a particular matrix element. The first method uses storage registers
R
0
and R
1
in the same way as described above  except that the row and
column numbers aren't automatically changed when User mode is
deactivated. The second method uses the stack to define the row and
column numbers.