A polynomial can be defined as an expression that consists of variables (or indeterminates) raised to non-negative integer powers, along with coefficients. The degree of a polynomial is determined by the highest power of the variable in the expression.
In the case of the number 3, it can be interpreted as a polynomial, specifically a constant polynomial. This is because any constant can be expressed as a polynomial with a variable raised to the power of 0. Therefore, the expression can be re-written as:
3 = 3x0
Here, x is the variable, and since the power is 0, the degree of this polynomial is 0.
In summary, the polynomial 3 is classified as a constant polynomial, and its degree is 0.