With communciation now on the web and in digital form, we may use both and a bit more.

    An example of such a digital format is found in a Geometer's Sketchpad at fX.f'X.f''X.intX.gsp

1. Edit a function as desired or use the one already on the sheet.
2. Draw the blue dot on the x-axis to the desired position and note the change in x, function, derivative, and second derivative values.
3. Select appropriate emoji(s) and move the emoji(s) to mark a desired characteristic of the function.

    Examples and a practice sheet follow.

    Enjoy