>	restart;  #problem #1

>	deriv_def:=Limit((f(x+Delta*x)-f(x))/(Delta*x),Delta*x=0);

>	f:=x->-2*x-3; #define our function

>	f(x+Delta*x);  #first term to be substituted in the definition above

>	f(x);  #second term in numerator above