Level Sets of a Function

   The need to solve equations has played a prominent role throughout the history of mathematics and has driven much of its development. Differential calculus provides tools to study solutions of equations, especially from a qualitative point of view. It will be advantageous to visualize the solution set of a given equation as a level set. Here is the precise definition.


Move on to
  • derivatives of multivariable functions
  • level sets, the implicit function theorem and implicit differentiation
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     Read: L sub f of eta is defined to be the set of all xi in D such that f of xi equals eta  Example of some of the level sets  View an explanation of the relationship between the level sets of a function and its graph  See in detail how this system of equations arises  Review the definition of a linear map  Take a look at the inverse function theorem  Take a look at the implicit function theorem  An example of a contour map  A quadratic polynomial whose level sets are ellipses  A quadratic polynomial whose level sets are hyperbolas  A quadratic polynomial whose level sets are parabolas  A quadratic polynomial whose level sets are ellipsoids  A quadratic polynomial whose level sets are cylinders  Try out some exercises