Finding Min/Max of a function for HP-67

[PedroLeiva]

(05-22-2016 01:11 AM)Dieter Wrote:  

(05-21-2016 10:50 PM)PedroLeiva Wrote:  1- What equation represents steps 55-62? How I entry an equation to be evaluated?

As usual, you enter f(x) at LBL E. The argument x is expected in the X-register. Here f(x) obviously is e^x–3x².

(05-21-2016 10:50 PM)PedroLeiva Wrote:  2- From my example 2,833 is a Max. or a min.? How to obtain both if corresponds?

Since f"(x) is stored in R3, you could simply inpect this value (RCL 3) an see whether it's positive (minimum) or negative (maximum).

Here the function has a minimum at x=2,833147892... (solution of f'(x) = e^x–6x = 0).
At ths point f"(x) = e^x–6 is 10,998887... > 0, so this is a minimum. The content of R3 should be close to the latter value.

Dieter

Dieter
It's more complicated than I imagined. Luckily I made the query. Thank you very much, Peter