Drag the blue handles to make one, two, or all three of the red roots disappear.

Notes:

Root[], which works, doesn't recognize polynomials as polynomials. Proof:
Type a polynomial in the input bar.
GGB correctly recognizes this as what kind of object?
Press the button.
(giggle)
The proof is complete.

Slumberland has tricked GGB into accepting the polynomial anyway. How?

The good news here, as always, is that since 11 year-olds are well versed in both numerical analysis and clumsy scripting languages --and can read our minds-- students won't find either the results or the syntax (examine it carefully) confusing.
If you know Slumberland, then you know that a broken tool is enough to get the Sleepy King to pose, set up, and solve the problem from scratch. Here, I have broken up the problem like this:
To find the real roots of a 3rd degree polynomialTo find the real roots of the trigonometric polynomials which arise from the intersection of conic sections.To find all roots (real and complex) of a polynomial of degree n (coefficents real or complex).
Since Slumberland breaks all the tools in Geogebra by trying to solve elementary mathematical problems in an ordinary way, he is in the middle of setting up and solving a very great number of problems whose solutions are, at present, a total blank to him.
Good.
Onward
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