# How do you find the local extrema for #f(x)= x^4-4x³#?

##### 1 Answer

Jun 28, 2016

#### Answer:

There is a minimum for

#### Explanation:

First of all we search the zeros of the derivative.

One solution is of course

To see which kind of points are

and we have

Then when

We can see this also from the plot.

graph{x^4-4x^3 [-52.9, 61.54, -29.3, 27.9]}