Here's an example of a program that you can use:lrdheat wrote: ↑Thu May 27, 2021 4:10 amHi Nigel,

I’m having difficulty typing/finding the symbol delta x or delta Greek d, even outside of a program. How do I find these characters? Do I call the program (symbol)delta (Greek) d? How do I type the delta (symbol) d (Greek character) into the label command?

LBL'\(\Delta X\)'

RCL 99

END

You enter the first line like this:

- LBL

- ENTER - enters alpha mode;

- SHIFT SHIFT D - enters capital Delta;

- X

- ENTER - leaves alpha mode and completes the label

I've tried using SLV along with the LBL'\(\Delta X\)' program above to find the zeros of the derivative of the function in your original post. With 0.1 stored in register 99 I get the result that you give; with 0.01 stored in register 99 I get 0.25 as the location of the extremum. So that seems to work!

Nigel (UK)