Is f(x)=(2x^3-5x^5-2)/(9x^2+9) a polynomials?

1 Answer
Jun 29, 2015

No, the ratio is not a polynomial. (The numerator and denominator separately are polynomials.)

Explanation:

A polynomial (in one variable) consists of terms (things added together), each of which is a constant (a number) times the variable raised to some positive whole number power (or just a constant alone).

2x^3-5x^5-2 is an example of a polynomial.
The terms are 2x^3 and -5x^5 and -2.
Actually, I've listed the terms with non0zero coefficient. If we want, we can also insert "terms" 0x^4 and 0x^2 and so on. (And even 0x^7 if there is a reason to add that term.)

The expression (2x^3-5x^5-2)/(9x^2+9) is called a Rational expression.

(And the function f(x) = (2x^3-5x^5-2)/(9x^2+9) is called a Rational Function.)