Question

How do you find the relative extrema for `y=x^3`?

Answer 1

Differentiate and check for points which the gradient is zero or undefined.

Explanation:

`frac{dy}{dx} = 3x^2`

`3x^2 = 0`

`x = 0`

However, the first derivative test shows that it is not an extremum, but rather an inflection point.