The ebook Elementary Calculus is based on material originally written by H.J. Keisler. For more information please read the copyright pages.


Example 4

EXAMPLE 4

04_integration-143.gif

Figure 4.2.10

Find 04_integration-140.gif (Figure 4.2.10). The function √t is defined and continuous on the half-open interval [0, ∞]. But to apply the Fundamental Theorem we need a function continuous on an open interval that contains the limit points 0 and 4. We therefore define

04_integration-141.gif

This function is continuous on the whole real line. In particular it is continuous at 0 because if t ≈ 0 then f(t) ≈ 0. The function

04_integration-142.gif

is an antiderivative of f. Then

04_integration-150.gif

In the next section we shall develop some methods for finding antiderivatives. The antiderivative of a very simple function may turn out to be a "new" function which we have not yet given a name.


Last Update: 2006-11-25