EQ for algebraic solvers


Greetings gentlemen,

Can anyone point me to a decent collection of equations to enter into algebraic solvers (i.e. HP 27S etc.)? A cursory search on google turned up little worthy of note.

Edited: 29 Dec 2003, 5:06 p.m.


Pick any equation you deem worthy to take up RAM and just key it in.

Like some paticular branch of science?

Grab a textbook and key in a couple of key equations and you have personalized you 27s. I knew an Electrician who set his 27s up to do Voltage drops with various guage wire and current loads. Simple and straight forward.

And your 27s can hold hundreds of eq if you reuse variables. Only flaw, no real I/O to save all those eq should you have a memory reset (which happened often with one of my 27s's).

Pick a field and I am sure someone can recommend many eq that are must haves.


[beg quote]
Pick any equation you deem worthy to take up RAM and just key it in.
[end quote]

Thanks a lot man, but I was looking for something more sophisticated than a+b=c. Here's a convenient example for you:



Hi, guys;

I have both HP19BII and HP17BII and I took a look at the excelent W. Bruce Maguire II listing. I would like to know if the HP27S offers the same structures and resources available in both HP17/19BII for algebraic expressions, I mean, decision structures, "external" call (for existing expressions), menu facilities... The fact is that the HP27S offers a lot of scientific resources along with the financial ones. Else, I'd like to know if the existing "bonus" resources in the HP19BII for math and science (trigs, logs, vector/complex resources) are related to the ones in the HP27S.

If so, almost all existing HP17/19BII programs may be used, or in the worst case, adapted.

Just curious about. I saw an HP27S when I was at the university, but I was not able to handle an algebraic HP while I could only think of RPN models... Too sad; that babe could be mine! :(


Luiz (Brazil)


A good resource would be the HP27S/HP19B Technical Applications manual. A scan of it is available on the MoHPC DVD.

It has a section on Advanced Solver Techniques followed by about a dozen example equations.

And yes Luis, it looks like the HP27S and HP19B/BII equations are fairly interchangable.

Mark Hardman

Edited: 29 Dec 2003, 10:47 p.m.


Nice example. The 27s can do that as well, but if you notice, only L (Let) and IF statements are used. There is also a G (Get) function. That is the total extent of programming that is available to this series calculators (the Hp17, Hp19, Hp27s). That is why they are not considered programmables. The solvers though are very complex and complete for the use they provide. None compare to an Hp42s, but that is another matter.

While that is example is very involved, the solver usually allows you to make sophisticated equations into simple plug and chug chores.


True, they're not programmable in the general sense, but you forgot about the SIGMA function. Using Let, Get, IF and Sigma (for iteration), it's possible to do some pretty substantial programming-like stuff.


Hi Katie,

You are being too humble--did you not post a really clever discovery about the sigma function a few months back?

Best regards,




I don't think that I posted anything about using SIGMA, just a bubble sort routine for the 12C. But here's something that I wrote using SIGMA in the HP200LX solver. It calculates pi to any number of decimal places using the 1-2-3 interface to store the partial and final results. To use it you need to have an LX (100, 200 and I think this will work on a 95). The STOCELL and RCLCELL functions just store and recall from the specified cell in 1-2-3. To use this, make the following an equation in the solver, start 1-2-3 and create a range called OUT. The number of rows in the range determines the number of digits of pi calculated -- 10 digits per row. The number of columns in the range is unimportant.

{!calculate Pi to n places into OUT in 1-2-3!


l(n,10000000000)*0+ !set the number of digits/cell!

sigma(x,1,length(out),1, !zero the output range!
stocell(0,out,x,1)+stocell(0,out,x,2) ) +

stocell(.28*g(n),out,1,1) + !initial value for 1st term!

SIGMA(x,length(out),1+l(c,0),-1, !add to result!
l(c,idiv( g(t),g(n)))*g(n),out,x,2)) +

sigma(i,2,2*log(g(n))*length(out)/log(50),2, !set up 1st term

SIGMA(x,l(c,0)+LENGTH(out),1, -1, !multiply by i!
out,x,1)) +

SIGMA(x,1+l(c,0),LENGTH(out),1, !divide by 50*(i+1)!
STOCELL(idiv((g(c)*g(n)+RCLCELL(out,x,1)),(i+1)*50) +
(i+1)*50)),out,x,1)) +

SIGMA(x,Length(out),1+l(c,0),-1, !add to result!
STOCELL(l(t,g(c)+RCLCELL(out, x,1)+RCLCELL(out,x,2)) -
l(c,idiv(g(t),g(n)))*g(n) ,out, x,2))) +

stocell(.030336*g(n),out,1,1) + !initial value for 2nd term!

SIGMA(x,length(out),1+l(c,0),-1, !add to result!
l(c,idiv( g(t),g(n)) ) * g( n) ,out,x,2)) +

SIGMA(i,2,2*log(g(n))*length(out)/log(6250/9),2, !setup 2nd
term loop!

SIGMA(x,l(c,0)+LENGTH(out),1, -1, !multiply by i*9!
STOCELL(mod((g(c)+i*9*RCLCELL(out,x,1)),g(n)) +
0*l( c, idiv((g(c)+i*9*RCLCELL(out,x,1)),
g(n))),out,x,1)) +

SIGMA(x,1+l(c,0),LENGTH(out),1, !divide by 50*(i+1)!
STOCELL(idiv((g(c)*g(n)+RCLCELL(out,x,1)),(i+1)*50) +
(i+1)*50)),out,x,1)) +

SIGMA(x,1+l(c,0),LENGTH(out),1, !divide by 125!
STOCELL(idiv((g(c)*g(n)+RCLCELL(out,x,1)),125) +
0*l( c,mod((g(c)*g(n)+RCLCELL(out,x,1)),125)),
out, x,1)) +

SIGMA(x,LENGTH(out),1+l(c,0),-1, !add to result!
l(c,idiv( g(t),g(n)) ) * g( n) ,out,x,2))

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