2.3: Interpretations of the derivative

Main Points
The derivative can also be denoted by f '(x) = dy/dx, where the 'd's is useful in reminding the user that the derivative is a difference in y-values over a difference in x-values. A derivative tells us how fast a function is changins thus enabling us to estimate the values of that function at points close to the derivative point.

Challenges
Under the "Using Units to interpret the Derivative," I do not understand the second point in the box.

Reflections
The derivative serves as an investigative tool that helps the user to compute certain figures pertinent to whatever situation they are in. I especially like the cost of building a house example (Example 2, p. 113)