Iterative calculation of exponent when not needed?

[Bill Duncan]

While working on some probability calculations using "solve" on an HP-27S, I was curious why an iterative solution was used while using logs would be faster? The equation was simply something like this:

Code:

X = Y ^ Z

Where I wanted to solve for Z. It chugged away displaying intermediate solutions while working it out. Why not simply..

Code:

Z = log(X) / log(Y)

I haven't tried it on my HP-48 yet. Would it resort to an iterative solution as well? What about TVM applications for solving for the number of periods? Iterative solutions? I haven't looked yet, but curious (and too late to investigate tonight)..

[brouhaha]

Because the 27S only solves equations numerically. It doesn't have any symbolic algebra code. It's only a slightly fancier version of the 34C/15C/Advantage solver.

[ijabbott]

(12-12-2023 06:43 AM)brouhaha Wrote:  Because the 27S only solves equations numerically. It doesn't have any symbolic algebra code. It's only a slightly fancier version of the 34C/15C/Advantage solver.

It can do a little bit of rearrangement to solve directly, but nothing fancy like applying logs!