[Free42] root finder

[Dieter]

(06-15-2016 09:12 PM)Marcio Wrote:  You're right.
I think it's more of an oddity than a bug. The 35s also requires only one guess and the minimum seems to be between 4 and 5. If it is 3, the 35s will return zero "exactly" instead of a very small number.

The 35s behaves exactly like the 42s in this regard. It uses two (2) guesses, where one is the value in the variable and the other is in X. When used in a program, the 42s solver does it exactly the same way. So on the 35s you would type 1 [STO][T] 10 if you want to start with 1 and 10, and then SOLVE T.

Of course you can always enter just one guess, or even nothing at all. Then the calculator uses what happens to be stored in the variable (T) and in X. I don't think this is a good idea.

(06-15-2016 09:12 PM)Marcio Wrote:  I'm sorry, I meant greater than 4. Try with 3 and 4 as guesses and the 15C will return a very small number which is interpreted as zero.

I think this is perfectly OK. There are two roots at 0 and 9,28. If you enter two guesses that are closer to zero the calculator returns this root, otherwise the other one.

Dieter