integration of fraction power expressions
The antiderivatives of every expression containing fraction powers can not be expressed by using elementary functions. However, there are after making a substitution.
- •
, where means a rational function of its arguments.If the common denominator of the fraction power exponents
is , the substitution
changes each exponent to an integer and the whole integrand to a rational function in the variable .
Example. For the least common multiple of the denominators of and is 4, whence we make the substitution , . Then we obtain
- •
In , correspondently the substitution
changes the integrand to a rational function.
Example. For we substitute , , getting
References
- 1 N. Piskunov: Diferentsiaal- ja integraalarvutus kõrgematele tehnilistele õppeasutustele. Viies, täiendatud trükk. Kirjastus “Valgus”, Tallinn (1965).