Using SLOPE function in Function APP with CAS defined function

[Han]

(12-08-2014 06:43 PM)cdecastro Wrote:  Here's a little problem I encountered with SLOPE.

in CAS, enter,

f(x):=x^2

then go to the Function App and enter f(X) to graph. Now try to obtain the slope using the SLOPE function and the calculator reports NaN.

FYI: The SLOPE function does work if I enter F1(x) = X^2 in the Function App and find the slope.

Thanks,
Chris

It does seem there is a bug with using CAS functions for the definition of the F0 through F9 variables. I think there was some discussion about this a while back.

That said, unless you plan to use the formula for f(x) for other calculations and you don't want it to affect F1, you can ignore creating f(x) and simply type:

F1(x):=x^2; // you can use any dummy variable, just be consistent
F2:=diff(F1); // this is "functional" derivative as opposed to the derivative with respect to a specific variable

F1 can be used like any regular function you create in the CAS.

On the other hand if you need to have f(x) separately defined, then:

f(x):=x^2;
F1:=f;

will do what you want.

As usual, this is only one of many ways to do what you want.