The critical points of <em>h(x,y)</em> occur wherever its partial derivatives
and
vanish simultaneously. We have

Substitute <em>y</em> in the second equation and solve for <em>x</em>, then for <em>y</em> :

This is to say there are two critical points,

To classify these critical points, we carry out the second partial derivative test. <em>h(x,y)</em> has Hessian

whose determinant is
. Now,
• if the Hessian determinant is negative at a given critical point, then you have a saddle point
• if both the determinant and
are positive at the point, then it's a local minimum
• if the determinant is positive and
is negative, then it's a local maximum
• otherwise the test fails
We have

while

So, we end up with

Answer:
1017.36 square miles
Step-by-step explanation:
Since the diameter of a circle is twice the radius, the radius of this circle is 36/2=18. Since the area of a circle is
, the area of this circle is:

Hope this helps!
Answer:
Triangle
Step-by-step explanation:
Area of a triangle
= 1/2 x base x height
Step-by-step explanation:
Let O be the center of the circle
We have Angle YOW = 125°
and Angle WOX = 121°.
Therefore Angle YOX = 360° - 125° - 121° = 114°.
(Sum of angles around a point is 360°)
Since Angle at Center = 2 * Angle at Circumference,
Angle YWX
= 0.5 * Angle YOX = 0.5 * 114° = 57°. (A)
C is the answer because the X factors can’t repeat