# What are the critical points of #x^2/9 + y^2/36 = 1#?

##### 2 Answers

The axes are

The center is

The foci are F

#### Explanation:

This is the equation of an ellipse.

The major axis

The minor axis

The center is

The foci are F

graph{(x^2/9)+(y^2/36)=1 [-14.24, 14.23, -7.12, 7.12]}

Critical points are

#### Explanation:

A critical point is a point on a curve, where either the derivative is not defined or its value is zero.

As

or

which is zero when

Note that when

Critical points are

In fact, it is an ellipse with major axis at

graph{x^2/9+y^2/36=1 [-20, 20, -10, 10]}