Question 718318
At what level of Algebra do you want to graph this?  You should factor the polynomial and you have something easier to analyze.

f(x)=x(x^2-2x-3)
{{{highlight(f(x)=x(x+1)(x-3))}}}


Roots at -1, 0, and 3.  At x<-1, f is increasing.  At x>3, f is increasing.  Between -1 and 0, f is positive. Between 0 and 3, f is negative.


{{{graph(300,300,-5,5,-20,20,x^3-2x^2-3x)}}}