Question: what is the difference of zero and root?
Answer: Root of a polynomial is that value of x that makes the polynomial equal to 0. if and only if P(r) = 0. So the difference is: whenever one has a function f : X→R one says that x* is a zero of f if f(x*) = . ... The rule of thumbs: Zero refers to the function (e.g. polynomial) and root refers to the equation.