Sign of a second partial derivative

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SUMMARY

The discussion focuses on determining the sign of a second partial derivative, specifically in the context of a function evaluated at the point (1,2). The method involves analyzing the behavior of the first derivative with respect to x while keeping y constant, and then assessing how this slope changes as y varies. This approach is crucial for understanding the concavity of the function in multivariable calculus.

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  • Understanding of multivariable calculus concepts
  • Familiarity with partial derivatives
  • Knowledge of slope analysis in two dimensions
  • Experience with evaluating functions at specific points
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  • Study the method of evaluating second partial derivatives
  • Learn about the implications of the second derivative test in multivariable functions
  • Explore graphical interpretations of partial derivatives
  • Investigate the use of Hessian matrices in determining concavity
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Students and professionals in mathematics, particularly those studying calculus, as well as educators teaching multivariable calculus concepts.

LCSphysicist
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I am not sure how to determine the sign of this derivatives.
(a) first we can pass a plane by (1,2) parallel to XZ (y fixed) and see how the curve belongs to the plane will vary with x, but what about the next partial derivative, with respect to y?
 
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At the point, look at the slope with respect to x. When the point moves slightly in the positive y direction, does the slope with respect to x increase or decrease?
 
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