Actually all the question is asking is the integral, or antiderivative of x^2
which if you've taken any calculus class (but i only took my first one last semester, so I wouldn't be suprised if lots of people haven't) is very simple to solve.
and f:= means that you define whatever is on the right side of the equal sign to be equal to f,
for example, in maple if I said
f:=fishsticks;
(you have to end commands with a semicolon) and then I put in
f; and just hit enter
it would look like this:
>f:=fishsticks;f:=fishsticks
>f;fishsticks