a special case of partial integration
In determining the antiderivative of a transcendental (http://planetmath.org/AlgebraicFunction) function whose derivative is algebraic (http://planetmath.org/AlgebraicFunction), the result can be obtained when choosing in the formula
of integration by parts ; then one has
The functions in question are mainly the logarithm (http://planetmath.org/NaturalLogarithm2), the cyclometric functions and the area functions.
Examples.
- 1.
- 2.
- 3.
- 4.
The choice works as well in such cases as and , giving respectively and (see logarithmic integral). Also , requiring two integrations by parts, and giving the result .