Question 131679
f(x)=x^3-27x-54
answers (-3,0),(6,0) & (0,-54)
{{{ graph( 500, 500, -10, 10, -100, 100, x^3 -27x -54) }}} 
 (graph 500x500 pixels, x from -10 to 10, y from -100 to 100, x^3 -27x -54).