In this video I explain what the heck we're talking about with linear approximations, and show you where the formulas come from while working a couple of examples. If you're not hot on tangent lines, definitely brush up on the tangent lines chapter, which also reviews the slope-intercept form of lines.
Linear Approximation Examples
In this video we'll work more examples (you're working these along with me, right?), as well as talking about error and percent error.
Not to be confused with "differential equations", differentials are just another type of linear approximation question they can ask. In this video I cover how to do them and how to figure out which formula to use on each type of problem, which can save you some serious work since differentials are a tiny bit easier than linear approximations.
If you do not have an account, you should get one, because it is awesome! You can save a playlist for each test or each chapter, and save your "greatest hits" into a "watch right before the final" list (not that we recommend cramming, but when in Rome...)