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is the fractional derivative (if q > 0) or fractional integral (if q < 0). If q = 0, then the q -th differintegral of a function is the function itself. In the context of fractional integration and differentiation, there are several definitions of the differintegral.
The theory of fractional integration for periodic functions (therefore including the "boundary condition" of repeating after a period) is given by the Weyl integral. It is defined on Fourier series , and requires the constant Fourier coefficient to vanish (thus, it applies to functions on the unit circle whose integrals evaluate to zero).
Integration is the basic operation in integral calculus.While differentiation has straightforward rules by which the derivative of a complicated function can be found by differentiating its simpler component functions, integration does not, so tables of known integrals are often useful.
A line integral (sometimes called a path integral) is an integral where the function to be integrated is evaluated along a curve. [42] Various different line integrals are in use. In the case of a closed curve it is also called a contour integral. The function to be integrated may be a scalar field or a vector field.
If the differ integral is initialized properly, then the hoped-for composition law holds. The problem is that in differentiation, information is lost, as with C in the first equation. However, in fractional calculus, given that the operator has been fractionalized and is thus continuous, an entire complementary function is needed.
This visualization also explains why integration by parts may help find the integral of an inverse function f −1 (x) when the integral of the function f(x) is known. Indeed, the functions x(y) and y(x) are inverses, and the integral ∫ x dy may be calculated as above from knowing the integral ∫ y dx.
These reduction formulas can be used for integrands having integer and/or fractional exponents. Special cases of these reductions formulas can be used for integrands of the form ( a + b x + c x 2 ) p {\displaystyle \left(a+b\,x+c\,x^{2}\right)^{p}} when b 2 − 4 a c = 0 {\displaystyle b^{2}-4\,a\,c=0} by setting m to 0.
Many special functions appear as solutions of differential equations or integrals of elementary functions.Therefore, tables of integrals [1] usually include descriptions of special functions, and tables of special functions [2] include most important integrals; at least, the integral representation of special functions.