The ebook Elementary Calculus is based on material originally written by H.J. Keisler. For more information please read the copyright pages. |
![]() |
Home ![]() ![]() ![]() |
|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
|
Definite Integration By Parts
Integration by parts requires a great deal of guesswork. Given a problem ∫ h(x) dx we try to find a way to split h(x) dx into a product f(x) g'(x) dx where we can evaluate both of the integrals ∫ g'(x) dx and ∫ g(x) f'(x) dx. Definite integrals take the following form when integration by parts is applied. DEFINITE INTEGRATION BY PARTS If u = f(x) and v = g(x) have continuous derivatives on an open interval I, then for a, b in I, PROOF The Product Rule gives f(x) g'(x) dx + g(x)f'(x) dx = d(f(x) g(x)). Then by the Fundamental Theorem of Calculus, and the desired result follows by the Sum Rule. If we plot u = f(x) on one axis and v = g(x) on the other, we get a picture of definite integration by parts (Figure 7.4.1). The picture is easier to interpret if we change variables in the definite integrals and write the formula for integration by Figure 7.4.1 Definite Integration by Parts parts in the form
|
|
Home ![]() ![]() ![]() |