Fractional Derivative

The fractional derivative of of order
(if it exists) can be defined in terms of
the fractional integral
as
![]() |
(1)
|
where is an integer
, where
is the ceiling
function. The semiderivative corresponds to
.
The fractional derivative of the function is given
by
![]() | ![]() | ![]() |
(2)
|
![]() | ![]() | ![]() |
(3)
|
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(4)
|
![]() | ![]() | ![]() |
(5)
|
![]() | ![]() | ![]() |
(6)
|
for . The fractional derivative
of the constant function
is then given
by
![]() | ![]() | ![]() |
(7)
|
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(8)
|
The fractional derivate of the Et-function is given by
![]() |
(9)
|
for .
It is always true that, for ,
![]() |
(10)
|
but not always true that
![]() |
(11)
|
A fractional integral can also be similarly defined. The study of fractional derivatives and integrals is called fractional calculus.