A polynomial with a degree of 4 is expressed as a sum of terms, each of which is a constant multiplied by a variable raised to an integer power, where the highest power is 4.
For example, the expression 2x4 + 3x3 – x + 5 is a polynomial of degree 4. Here, the term 2x4 indicates that the highest exponent of the variable x is 4, making this a fourth-degree polynomial.
In contrast, an expression like 3x2 + 2 would not be classified as a degree 4 polynomial because its highest degree term is x2. To summarize, for an expression to be a polynomial of degree 4, it must have at least one term where the variable x is raised to the power of 4, along with any additional terms of lower degree.