# Is #f(x) =(x-9)^3/(x^2/3+1)# concave or convex at #x=9#?

##### 1 Answer

Sep 29, 2017

Neither.

#### Explanation:

At x=9, The function is zero, its first derivative is zero, its second derivative is zero, and so on.

So the function is neither concave nor convex at x = 9.