Stationary Point after Partial Differentiation

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SUMMARY

The discussion centers on finding stationary points of the function f(x,y) = x^2 + 8xy^2 + 2y^2 through partial differentiation. The equations df/dx = 2x + 8y^2 = 0 and df/dy = 16xy + 4y = 0 are established for this purpose. The conclusion drawn is that y can be zero or that the equation 16x + 4 = 0 can be solved to find x = -1/4. The realization that y was factored out clarifies the solution process for determining stationary points.

PREREQUISITES
  • Understanding of partial differentiation
  • Familiarity with stationary points in multivariable calculus
  • Knowledge of solving algebraic equations
  • Basic proficiency in calculus concepts
NEXT STEPS
  • Study the method of finding stationary points in multivariable functions
  • Learn how to apply the second derivative test for functions of two variables
  • Explore the implications of stationary points in optimization problems
  • Review factoring techniques in algebra for solving equations
USEFUL FOR

Students studying calculus, particularly those focusing on multivariable functions and optimization, as well as educators looking for examples of partial differentiation applications.

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Homework Statement


A question in a book has partially differentiated a function

f(x,y) = x^2 + 8xy^2 + 2y^2

df/dx = 2x + 8y^2 = 0 at stationary point (eqn 1)
df/dy = 16xy + 4y = 0 at stationary point (eqn 2)


Homework Equations





The Attempt at a Solution



It then states;

From (eqn 2) either
y = 0, or 16x + 4 = 0
y = 0, or x = -1/4

I can understand how y=0, but how do they conclude that 16x + 4 = 0

Thank you
 
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I've realized they've just factored out the y!
 

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