Rewrite using a substitution Do not integrate 7
Re-write using a substitution. Do not integrate. ? ? ?
7. 1 Integration By Parts Start with the product rule: This is the Integration by Parts formula.
u differentiates to zero (usually). dv is easy to integrate. Or for a definite integral The Integration by Parts formula is a “product rule” for integration. Choose u in this order: LIPET Logs, Inverse trig, Polynomial, Exponential, Trig
When do you use Integration by Parts (IBP)? • Usually, the function is the product of 2 different types of functions. Polynomial, log, exponential, trig, etc. • U-substitution does not produce a known pattern to integrate. 2 different types of functions, but… 2 different types of functions, and no u-sub works.
Example 1: LIPET polynomial factor
Example: LIPET logarithmic factor
Example 4: LIPET This is still a product, so we need to use integration by parts again.
Example 5: LIPET This is the expression we started with!
Example 6: LIPET
Example 6: This is called “solving for the unknown integral. ” It works when both factors integrate and differentiate forever.
A Shortcut: Tabular Integration Tabular integration works for integrals of the form: where: Differentiates to zero in several steps. Integrates repeatedly.
Compare this with the same problem done the other way:
Example 5: LIPET This is easier and quicker to do with tabular integration!
p
Doesn’t follow any pattern for integration that we know.
What if… So instead: Then…
Homework: Page 492 5, 11, 19, 27, 31, 35, 39, 57, 61, 64 b
- Slides: 18