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8.2 Integration By Parts. Start with the product rule:. Integration by Parts. dv is easy to integrate. u differentiates to zero (usually). The Integration by Parts formula is a “product rule” for integration. Choose u in this order: LIPET.
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8.2 Integration By Parts
Integration by Parts dv is easy to integrate. u differentiates to zero (usually). The Integration by Parts formula is a “product rule” for integration. Choose u in this order: LIPET Logs, Inverse trig, Polynomial, Exponential, Trig
Example LIPET polynomial factor
Example LIPET logarithmic factor
Example LIPET This is still a product, so we need to use integration by parts again.
A Shortcut: Tabular Integration Tabular integration works for integrals of the form: where: Differentiates to 0 in several steps. Integrates repeatedly. Example:
This is called “solving for the unknown integral.” It works when both factors integrate and differentiate forever. Example This is the expression we started with!
How to choose u and dv • Try to choose u so that du (its derivative) becomes easier to integrate than u. • If ln is present, then u must be ln. • Oftentimes, let u be the powers of x. • Also, choose dv so that it is easy to integrate dv. • Ifexis present, let dv = exdx • Oftentimes, let dv be the sin or cos. • After integrating by parts, you should wind up with the integral that is “easier” to integrate.