At a zoo, the lion pen has a ring-shaped sidewalk around it. The outer edge of the sidewalk is a circle with a radius of 12 m. T
he inner edge of the sidewalk is a circle with a radius of 8 m.
Write and simplify an expression for the exact area of the sidewalk.
Find the approximate area of the sidewalk. Use 3.14 to approximate π.
Write and simplify an expression for the exact area of the sidewalk.
Find the approximate area of the sidewalk. Use 3.14 to approximate π.
1 answer:
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Answer:
A(-1,0) is a local maximum point.
B(-1,0) is a saddle point
C(3,0) is a saddle point
D(3,2) is a local minimum point.
Step-by-step explanation:
The given function is
The first partial derivative with respect to x is
The first partial derivative with respect to y is
We now set each equation to zero to obtain the system of equations;
Solving the two equations simultaneously, gives;
and
The critical points are
A(-1,0), B(-1,2),C(3,0),and D(3,2).
Now, we need to calculate the discriminant,
But, we would have to calculate the second partial derivatives first.
At A(-1,0),
and
Hence A(-1,0) is a local maximum point.
See graph
At B(-1,2);
Hence, B(-1,0) is neither a local maximum or a local minimum point.
This is a saddle point.
At C(3,0)
Hence, C(3,0) is neither a local minimum or maximum point. It is a saddle point.
At D(3,2),
and
Hence D(3,2) is a local minimum point.
See graph in attachment.
