hi there, i am actually studying about functional equation.
I got stucked with some derivatives problem,
and where i could find nowhere to refer or study from,
because it seems it is out of university book level.
my question is this :
what does it means by taking derivative with respect to partial derivative?
can anyone visualize this idea to me?
because i couldn't figure out the term with respect to partial derivative,
when it comes to a functional equation,
of which is a differential equations.
For e.g : F(x,y(x),y'(x),y''(x)) , find of F(x,y(x),y'(x),y''(x)) / y' .
How can we write the full solution with partial derivative respect to y' ? and how bout y''?