Extremum Graphical Fails

[lrdheat]

I notice that the Prime comes up with a “No minimum or maximum found” on a number of functions in the graph app.

An example is the graph of d/dx (COS (X)/(1+(SIN(x))^2).

I’m wondering why this is the case...

[essen]

(03-12-2021 03:22 AM)lrdheat Wrote:  I notice that the Prime comes up with a “No minimum or maximum found” on a number of functions in the graph app.

An example is the graph of d/dx (COS (X)/(1+(SIN(x))^2).

I’m wondering why this is the case...

Set angle mode to radians. Then it will, at least something of it.

Should be:
Y=1 for X=0+2*pi*n (n=integer, plus or minus).
Y=-1 for X=-pi+2*pi*n (n=integer, plus or minus).
- ?

Not the only error. It' s not possible to correct errors on this calculator. As it were build with a mistaken coding language paradigm. Its memory separation has confused the creators themself. It was also a serious mistake not to use aprostrophized variables, instead of stringing. All but a few command function does not work if variables are apostrophized. The stringing gives unsolvable problems with purging and storing and handling lists holding variables not stringed, as these variables will evaluate at any action on them. Stringing them as required in this abnormal language, are not compatible with what stringing are for in programming.

Nobody of the people who keeps favoring this calculator has ever made any
serious programming running on it. Otherwise they would had known.

Manufacturers of such defective pieces should be proceeded against, when not
being honest about it, trying to hide it.

[lrdheat]

Perhaps the graphing app does not analyze extremums for some d/dx functions. When I took d/dx symbolically of the function that failed, and entered that into the graphing app, it found the extremums.

[robmio]

Hello, I tried these steps:
I entered in F1 (X) d(Cos(x)/(1+Sin(x)^2))/dx: I requested the calculation of the extreme and I obtained: "No minimum or maximum found".
I entered the explicit derivative on F2(X): I requested the calculation of the extreme: the calculator has calculated it.
I again requested the calculation of the extreme of the function F1(X): this time the calculator has calculated it.
Strange, right?

[lrdheat]

My example (post 1) works now with new beta update!