Let the function $$ f $$ be defined by the equation:
$$ f(x) = ax^3 + bx^2 + cx + d $$
Given that the function is increasing for all real values of $$ x $$, what can be inferred about the coefficients $$ a $$, $$ b $$, $$ c $$, and $$ d $$?
If $$ a = 2 $$, $$ b = 0 $$, $$ c = 3 $$, and $$ d = -5 $$, what is the expression for the derivative of the function, and what does it tell us about the function's behavior?