Is the Definition for Fractional Derivative Correct?

In summary, the conversation discusses the expression for a Fractional integral of arbitrary order and the corresponding Fractional derivative. It is mentioned that setting r=-p can result in the Fractional derivative form of the integral, and the correctness of this definition is questioned. A reference to examples sheets for a first year calculus course is also provided.
  • #1
eljose
492
0
from the expression for a Fractional integral of arbitrary order:

[tex]D^{-r}=\frac{1}{\Gamma(r)}\int_c^xf(t)(x-t)^{r-1}[/tex]

if we set r=-p then we would have for the Fractional derivative:

[tex]D^{p}=\frac{1}{\Gamma(-p)}\int_c^xf(t)(x-t)^{-(p+1)}[/tex]

is my definition correct?..i mean if its correct to introduce the change of variable r=-p to obtain fractional derivative form fractional integral...

where [tex]\pi/{\Gamma(-p)}=\Gamma(p+1)sen(p+1)\pi[/tex]
 
Last edited:
Physics news on Phys.org
  • #2
The idea of *a* fractional derivative is well known. If you look over the examples sheets for the first year calculus course at www.maths.bris.ac.uk/~madve[/URL] you'll find it explained on there somewhere I think.
 
Last edited by a moderator:
  • #3



Based on the given expression, the definition for fractional derivative appears to be correct. The change of variable r=-p is a valid mathematical operation and does not change the validity of the definition. The resulting expression for the fractional derivative also follows the general form for fractional derivatives, with the integration being over a specific interval and involving the function f(t) and its derivatives. Furthermore, the use of the gamma function in the denominator is also consistent with the definition of fractional derivatives. Therefore, it can be concluded that the given definition for fractional derivative is correct.
 

What is a fractional derivative?

A fractional derivative is a mathematical operator that extends the concept of a derivative to non-integer orders. It is used to describe the rate of change of a function at a specific point, similar to how a traditional derivative measures the slope of a curve at a point.

How is a fractional derivative calculated?

A fractional derivative is calculated using a mathematical formula called the Riemann-Liouville derivative. This formula involves integrating the function over a certain interval and then applying a power function to the result.

What is the physical significance of a fractional derivative?

A fractional derivative has many applications in science and engineering, particularly in fields where systems exhibit non-integer order behavior. It can be used to model phenomena such as diffusion, viscoelasticity, and fractals, among others.

How is a fractional derivative different from a traditional derivative?

The main difference between a fractional derivative and a traditional derivative is that the former can be applied to non-integer orders, while the latter can only be applied to integer orders. Additionally, the fractional derivative of a constant is not zero, unlike in traditional calculus.

What are some examples of real-world applications of fractional derivatives?

Fractional derivatives have a wide range of applications in various fields of science and engineering. Some examples include modeling the spread of diseases, analyzing the behavior of financial markets, and understanding the properties of materials with complex structures, such as foams and gels.

Similar threads

Replies
1
Views
2K
Replies
16
Views
2K
Replies
5
Views
1K
Replies
4
Views
343
Replies
2
Views
1K
  • Calculus
Replies
29
Views
711
Replies
2
Views
284
Replies
1
Views
931
  • Differential Geometry
Replies
2
Views
588
Replies
1
Views
1K
Back
Top