# What are the extrema of #f(x) = x^3 - 27x#?

##### 1 Answer

Nov 1, 2015

#### Answer:

#### Explanation:

Relative maximum and minimum points occur when the derivative is zero, that is when

So in this case, when

#=>x=+-3.

Since the second derivative

But:

graph{x^3-27x [-115.9, 121.4, -58.1, 60.5]}