Apologies if there is an obvious answer to this…
My question concerns how Wolfram Alpha determines what is a function and what is a simple variable. In particular:
if I enter:
D[x^2*y^2,y]
I get the partial derivative with respect to y - i.e.
2x^2y
If I enter:
D[x^2*y^2,y],D[x^2*y^2,x]
I get both partial derivatives - i.e.
2x^2y and 2xy^2.
However if I just enter:
D[x^2*y^2,x]
then it assumes that y is a function of x and I get the answer:
d/dx(x^2 y^2) = 2 x y (x y'(x)+y).
Is there some way to control this behaviour - e.g. in this case if I enter something like
D[x^2*y^2,x]
make the system assume y is a variable and not a function.