A polynomial must be equivalent to an expression with a finite number of terms all of which are in the form ħAxN where N is a non-negative whole number, which includes 0, but not negative numbers. A can be any number, positive, negative or 0. f(x) =is not a polynomial because it has a variable in a denominator. Its numerator is a polynomial and its denominator is a polynomial, but f(x) itself is not a polynomial. Even if it is written as f(x) = and then as f(x) = where x is not = 0, its terms are not of the form ħAxN, where A is any number and N a non-negative whole number. And even if it is further written as f(x) = where x is not = 0, its terms are not of the form ħAxN, where A is any number and N a non-negative whole number. So f(x) cannot be changed into a finite number of terms all of the form AxN, where A is any number and N a non-negative whole number. So f(x) is not a polynomial. Edwin