# Section 1.2

Mathematical Models: A Catalog of Essential Functions

The following videos are lecture videos covering the material from Section 1.2 in Stewart’s Calculus 8th edition. Each major topic in the section is broken down into a short video.

This first video discusses linear models and their associated linear functions.

The next video discusses polynomial functions, which are some of the nicest functions. The domain of any polynomial function is **always** all real numbers.

In this video we discuss rational functions which get their name by being ratios of polynomial functions. Remember that the domain of a rational function does not include any numbers which make its denominator zero!

In this video we discuss some of the other *algebraic* functions such as power, root, exponential and logarithmic functions. Pay close attention to the restrictions on the domains of each type of function in this category!

Finally, we finish up with everyone’s favorite functions, the trigonometric functions. If you have not taken trig, it IS a pre-requisite for Calculus I and we will not be reviewing this material so I suggest you seek out a reference immediately to being studying the necessary trigonometry.

Exercise 1.2.1 Classifying Functions

Exercise 1.2.5 Finding Domain

Exercise 1.2.7 Families of Linear Functions