What is the polynomial form?

Polynomials are simply functions that you see all the time

A second degree polynomial would look like:

y = ax^2 + bx + c

That is because the largest power is to the 2.

A third degree polynomial would be raised to the third power when it's the biggest number:

y = ax^3 + bx^2 + cx + d

The a, b, c, and d are just variables for any number