Math 31: Curve Sketching Example 6 Lesson

This video is about sketching y=x^(1/3)(x-3).

[ABC-wkpt]

7:31 How do you tell whether it's a vertical or horizontal tangent? Did you assume it's a vertical tangent because there is an intercept when X=0 in the original function, and therefore it's impossible to have a horizontal tangent?