Thinking about the graph of y, the rate of change is zero whenever there is an extremum.
First, differentiate y.
[tex]y'=6x^2+6x-12[/tex]
Next, find the zeros of y' by factoring.
[tex]6(x^2+x-2)=0 \\ x = -2, x = 1[/tex]
Now, we substitute these x-values into the original equation to find the coordinates.
[tex](-2,21), (1,-6)[/tex]