Find the global max/min for z=xy^2 - 5 on the region bounded by y=x

In summary, the global maximum for z in the given region is 0, occurring at the point (0,0), and the global minimum is -5, occurring along the line y=x. To find the global maximum/minimum, critical points must first be identified, and then z values at these points are compared to those along the boundary. The global maximum/minimum can occur at a point on the boundary, and in this case, the global minimum is along the line y=x. The global maximum/minimum is not unique in this region, as there is another local minimum at the point (0,0). The shape of the region plays a significant role in determining the location of the global maximum/minimum, as extending the region
  • #1
countzander
17
0
Find the global max/min for z=xy^2 - 5 on the region bounded by y=x and y=1-x^2 in the xy-plane.
 
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  • #2


And what have you done so far?
 
  • #3


I found the critical point of z=xy^2 - 5 at (0,0), but I do not know how to relate this to the boundary.
 

Related to Find the global max/min for z=xy^2 - 5 on the region bounded by y=x

1. What is the global maximum/minimum for z in the given region?

The global maximum for z in this region is 0, which occurs at the point (0,0). The global minimum for z in this region is -5, which occurs along the line y=x.

2. How do you find the global maximum/minimum for z in this region?

To find the global maximum/minimum for z, we first need to find any critical points within the region. These are points where the partial derivatives of z with respect to x and y are both equal to 0. Then, we can evaluate the z values at these critical points and compare them to the z values along the boundary of the region to determine the global maximum/minimum.

3. Can the global maximum/minimum occur at a point on the boundary of the region?

Yes, the global maximum/minimum can occur at a point on the boundary of the region. In fact, in this case, the global minimum occurs along the line y=x, which is a boundary of the given region.

4. Is the global maximum/minimum unique in this region?

No, the global maximum/minimum is not unique in this region. In this case, the global minimum occurs along the line y=x, and there is another local minimum at the point (0,0).

5. How does the shape of the region affect the location of the global maximum/minimum?

The shape of the region can greatly affect the location of the global maximum/minimum. In this case, the region is bounded by the line y=x, which contains a local minimum for z. If the region were extended beyond this line, the global minimum would no longer be at this point.

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