HP 33s - Manual (Page 247)

Mathematics Programs 15–25
Program Lines:
(In RPN mode)
Description
Checksum and length: C7A6 51
Starts fourth–order solution routine.
º 4a
2
.
a
3
.
º a
32
.
. 4a
2
– a
32
.
º a
o
(4a
2
– a
32
).
a
1
.
º a
12
.
. b
0
=a
0
(4a
0
– a
32
) – a
12
.
! Stores b
0
.
a
2
.
-+. b
2
= –a
2
.
! Stores b
2
.
a
3
.
º a
3
a
1
.
º 4a
0
.
. b
1
= a
3
a
1
– 4a
0
.
! Stores b
1
.
To enter lines D0021 and D0022;
press 4 |  3.
º
ª
- Creates 7.004 as a pointer to the cubic coefficients.
% Solves for real root and puts a
0
and a
1
for
second–order polynomial on stack.
¶ Discards polynomial function value.
% Solves for remaining roots of cubic and stores roots.
% Gets real root of cubic.
! Stores real root.