# What are the values and types of the critical points, if any, of #f(x,y)=4y(1 - x^2)#?

##### 1 Answer

There are two critical points, with coordinates

#### Explanation:

Let

After setting both of these partial derivatives equal to zero, we get that

The second-order partial derivatives are

This discriminant is negative at both critical points, making them both saddle points.