This topic is in the 'Polynomials and Polynomial Functions' section. There are a lot of interesting ways for us to build up functions using variables. The simplest thing we can do is combine variables with integers using multiplication, addition, and subtraction. That's what we have with linear functions. But things become a lot more interesting when we allow ourselves to play with variables that have exponents bigger than 1. So if we raise a variable to a power, and combine a bunch of variables raised to different powers together, we'll get a very interesting function called a polynomial. Amazingly these polynomials end up having the same kinds of properties that we're used to seeing with plain old numbers, and that is truly amazing:).