HP 15c User Manual
Page 89
Section 4: Using Matrix Operations
89
For example, let matrix A be
1
1
2
1
1
1
2
1
10
3
40
A
.
The HP-15C correctly calculates A
−1
to 10-digit accuracy as
1
2
1
2
4
3
1
3
2
1
A
.
Now let
20
20
20
10
0
0
0
10
0
0
0
10
R
L
so that
40
40
40
40
10
10
2
10
10
1
2
1
3
E
.
E is very near a singular matrix
0
0
2
0
0
1
2
1
3
S
and ||E – S|| / ||E|| = ⅓ × 10
–40
. This means that K(S) ≥ 3 × 10
40
, so it's not surprising that the
calculated E
–1
9
9
9
9
10
11
10
142
.
2
10
284
.
4
07155
.
0
10
284
.
4
10
569
.
8
8569
.
0
10
1
10
67
.
6
1
E
is far from the true value
40
40
40
40
40
10
10
2
1
10
2
10
4
3
1
3
10
2
1
E