This topic is in the 'Polynomials and Nonlinear 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 cool:) Now once you wrap your head around the polynomials tutorials in this chapter, you'll get to have your mind blown once again with our nonlinear function tutorials. Here you'll learn about exponential functions, which help us understand many thing, including how money grows with interest in a bank. You'll also see some interesting ideas related to sequences and inverse variation. This section has some fairly advanced stuff and you'll see it in Algebra 1 courses too!