Answer: An expression is not considered a polynomial if it meets any of the following criteria:
Step-by-step explanation: 1. It contains a variable raised to a negative power or a fractional power. For example, x^-2 or x^(1/3).
2. It contains a variable inside a radical (square root, cube root, etc.). For example, √x or ∛x.
3. It contains a variable in the denominator of a fraction. For example, 1/x.
4. It contains a variable multiplied by itself with a coefficient that is not a constant. For example, 2x^2 or 3x*x.
5. It contains a variable raised to a non-integer power. For example, x^π or x^√2.
6. It contains a variable in the exponent of another variable. For example, x^y.
If any of these conditions are met, the expression is not a polynomial.