In Try This 3 you may have noticed that it is possible to add or subtract functions using only their graphs. Watch Adding Functions to see two added functions. Compare this strategy to your strategy.
Subtracting functions follows a nearly identical process, except that the y-values are subtracted instead of being added.
Read “Example 3” on pages 480 to 481 of the textbook to see an example of how functions can be added by using their graphs. Compare the method of adding the y-coordinates of corresponding points to the methods you have seen so far.
To see how the sum of two functions is affected by manipulating the individual functions, try Adding and Subtracting Functions, which gives the function (f + g)(x) = f(x) + g(x) and allows you to manipulate f(x) and g(x) to see how (f + g)(x) changes. Try both the addition and subtraction functions.
