Monday 8 th November, 2010 Introduction
Objective: Derive the formula for integration by parts using the product rule
Deriving the Formula Start with the product rule: This is the Integration by Parts formula.
u differentiates to zero (usually). dv is easy to integrate. Choose u in this order: LIPET Logs, Inverse trig, Polynomial, Exponential, Trig Choosing u and dv
Formula for Integration by parts The idea is to use the above formula to simplify an integration task. One wants to find a representation for the function to be integrated in the form udv so that the function vdu is easier to integrate than the original function.
Objective: Use the integration by parts formula for combinations of functions
Example 1: polynomial factor LIPET
Example 2: logarithmic factor LIPET
This is still a product, so we need to use integration by parts again. Example 3: LIPET
Example 4: LIPET This is the expression we started with!
Example 4(cont.): LIPET This is called “solving for the unknown integral.” It works when both factors integrate and differentiate forever.
Exercise