Stationary Values Homework: Find Co-ordinates & Nature

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Homework Statement


I have been asked to answer the following:

The function (x^3)+(y^3)-(2x^2)-(2y^2)+(3xy) has two stationary values. Determine their co-ordinates and their nature.


Homework Equations





The Attempt at a Solution


Sorry I am stuck.
 
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keighley said:

Homework Statement


I have been asked to answer the following:

The function (x^3)+(y^3)-(2x^2)-(2y^2)+(3xy) has two stationary values. Determine their co-ordinates and their nature.


Homework Equations





The Attempt at a Solution


Sorry I am stuck.
Your textbook should have a section on finding stationary points for functions of two variables. I'm reasonably certain it will also have a worked example or two.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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