answer:
The points on the graph where the tangent line is horizontal are precisely the points where first derivative is 0.
Here, we have f(x)=x^3 - 2
So, f'(x)=3x^2
f'(x)=0 implies 3x^2=0 which is possible only when x=0.
Therefore, x=0 is the only point on the graph of f(x)=x^3 - 2 where the tangent line is horizontal.