Can absolute value functions be considered polynomial functions?

[LordCalculus]

Are lx³l or lxl³ polynomials?

If not, what would be a good example of a cubic polynomial function (R $$\rightarrow$$ R) that doesn't cover all real numbers in its codomain?

 

[HallsofIvy]

Answer to your first question- no, they are not polynomials.

Answer to your second question, there is none. Every cubic polynomial has range all real numbers.