Finding Min/Max of a function for HP-67

[PedroLeiva]

This calculates –sign(f"(x)). So after the program has finished, a simple X<>Y will show –1 (minimum) or +1 (maximum).
Dieter
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The point is that in the original post of this program was no explanation about how to determine Max. or min. (or I did not realize).

From the two options for cheking, I prefer: x<>y (+1, -1), for Max. & min., respectively. This one is more intuitive (+ is related to Max.), the other procedure is inverse.
Thank you for clarifying this math issue, and modifying the program

Pedro