Thinking about the graph of f(x), the rate of change is zero whenever there is an extremum.
First, differentiate f(x)
[tex]f'(x)=3x^2+8x[/tex]
Next, find the zeros of f'(x) by factoring.
[tex]x(3x+8)=0 \\ x= \frac{-8}{3},x=0[/tex]
Now, we substitute these x-values into the original equation to find the coordinates.
(-2.667, 11.481), (0, 2)