It does not work what am I doing wrong?

[C.Ret]

(01-10-2022 01:14 PM)tom234 Wrote:  I tried this in app's FUNCTION, Advanced Function, and 3D Graphing still nothing.

It is not because the expression you enter works with a Texas Instruments that it is expected to be exactly the same on an Hewlett Packard.

The HP Prime, like any other HP calculators are not built to be fully compatible with the syntax and expression used on other calculator brands. Especially true when concerning a competitor such as a TI, for evident and historic reasons !

(01-10-2022 02:59 PM)Arno K Wrote:  The "where"-Operator does not seem to work in plot.

This is really true. And your workaround is nice. Especially if the function is assume to be zero out of the definition range.

But, there is an easy and direct way of indicating to the HP Prime Function plotter that the function is only defined in a given range : the PIECEWISE instruction.

1. Active the Function Application.
2. In the Function Symbolic View slot enter the following function definition : PIECEWIZE(-1≤X≤3 , 2*X-3 , ∞)
   Alternatively, press the "Math Template" button and touche the {…if ▫ structure to enter your definition the "Textbook" manner.
3. Press the Plot button and you will obtained the expected draw (see capture):    
   

P.S.: I don't understand why or what you reset several times and brick it out ? This way of making is operational since first year of production.