Is there any mathematical definiton of rational derivatives?
We all know y,y'',y''',...,y^(n) are orders of discrete numbers. Is there anything like one and a half 1,5th derivative of a function?
Firstly it may sound not consistent with definiton of derivatives. However it could make sense since we can calculate exponents of a number say 3^1, 3^2 and 3^(1,5) with continious exponents.
I have tried to google it, but all the results were about derivatives of rational functions.
Thanks.