Quiz 6: Classifying critical points


Problem 1.a) Find the critical points of f(x,y)=xy(x+y-1).

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Solving Systems of equations: A Review

Complete solution

 

1.b) Use the second derivative test to determine the type of the critical points that you found in 1.a).

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Complete solution

Problem 2) Suppose you know that (0,0) is a critical point of f, and you know that D(0,0) is not zero, but fyy(0,0) is. What kind of critical point is (0,0)?

A) A Max.

B) A Min.

C) A Saddle.


The Second Derivative Test: A Review

Problem 3) The combined length and girth (distance around) of a package sent through the mail cannot exceed 108 inches. If the package is a rectangular box, how large can its volume be?

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Complete solution

How to solve Max Min problems


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Created: April 16, 1997. Last modified: May 16, 1997.