The document discusses combining functions through addition, subtraction, multiplication, and division. Some key points: - Functions can be combined using the same rules as algebraic expressions, such as f(x) + g(x) = (f + g)(x). - An example demonstrates combining two functions f(x) and g(x) through addition, subtraction, multiplication, and division. - Composite functions are discussed where the output of one function acts as the input for another function, written as f(g(x)). - Several examples demonstrate evaluating composite functions by first evaluating the inner function and then the outer function. - It is shown that f(g(x)) is not