Re: HP55 had potential Message #11 Posted by Gerson W. Barbosa on 31 Mar 2012, 9:17 p.m., in response to message #10 by Luiz C. Vieira (Brazil)
Hello Luiz,
I would have loved the HP55! Back then ('82) I had a TI51III (same as TI55). I had just learned Calculus (or at least I thought I had :) and knew no numerical methods at all, but I tried the very limited numerical integration program below. Those were the days!
Cheers,
Gerson.
00 RCL 16 2
01 1 17 RCL
02 * 18 3
03 RCL 19 +
04 2 20 1
05 f(x) ;(*) 21 =
06 = 22 STO
07 SUM 23 3
08 0 24 +/
09 RCL 25 +
10 2 26 RCL
11 + 27 4
12 RCL 28 =
13 1 29 1/x
14 = 30 RST
15 STO
(*) f(x) is any of the following builtin functions:
sin, cos, tan, sinh, cosh, tanh, log, ln(x), e^x, 10^x, sqrt(x) or 1/x.
Usage:
n > STO 4
(ba)/n > STO 1
(RCL 1)/2 + a > STO 2
0 > STO 0 STO 3
2nd RST 2nd R/S
when the program stops on error,
press CLR RCL 0 to get the result
Example:
Integrate f(x) = sin(x) from a = 0 rd to b = 1 rd, using n = 50 intervals, should return 0.4597054.
Actual result is 0.4596977 (1  cos(1)).
Edited: 31 Mar 2012, 9:21 p.m.
