I assign a function like so: f:=x->0.2*x^2*(x-3)^3

Then using d/dx in the expression palette I differentiate: d/dx f(x)

Get the following: 0.6x^2 (x-3)^2 D(x^2)(x-3)

What is the "D" in the last expression? What hasn't the whole differentiation been completed?