Definition:Root of Mapping

Let $$f: K \to K$$ be a function on a field $$K$$.

Let $$x \in K$$.

Then the values of $$x$$ for which $$f \left({x}\right) = 0_K$$ are known as the roots of the function $$f$$.

This is simply a generalization of the case where $f$ is a polynomial.

Zero of a Function
The field $$K$$ is usually the set of real numbers $$\R$$ or complex numbers $$\C$$.

In this case, for a given function $$f$$, the roots are often called the zeroes of the function $$f$$