Some derivatives and limits with Maple
> f:=sqrt(x^2-4)/(x^3+2);
> g:=diff(f,x);
> h:=simplify(g);
> simplify(g-h);
> f:=cos(cos(cos(x)));
> f:=sin(10*x)/sin(9*x);
> limit(f,x=0);
>