Understand that a function from one set (called the domain) to another set (called the range) assigns to each element of the domain exactly one element of the range. Understand that if f is a function and 𝑥 is an element of its domain, then f(𝑥) denotes the output of f corresponding to the input 𝑥. Understand that the graph of 𝑓𝑓 is the graph of the equation 𝑦 = (𝑥).