Complex Variables Homework: Determine Set, Compute Derivative

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SUMMARY

The function f(z) = 1/(z^3 + 1) is analytic except at the points where the denominator equals zero, specifically at the roots of the equation z^3 + 1 = 0. These roots are z = -1, and the complex cube roots of unity, which are z = e^(iπ/3) and z = e^(-iπ/3). To compute the derivative, one can apply the quotient rule for complex functions, yielding df(z)/dz = -3z^2/(z^3 + 1)^2, valid in the domain where f(z) is defined.

PREREQUISITES
  • Understanding of complex functions and their properties
  • Familiarity with the concept of analyticity in complex analysis
  • Knowledge of the quotient rule for differentiation
  • Ability to solve polynomial equations in the complex plane
NEXT STEPS
  • Study the properties of analytic functions in complex analysis
  • Learn about the roots of polynomials and their implications for function behavior
  • Explore the quotient rule for complex derivatives in more detail
  • Investigate the Cauchy-Riemann equations and their role in determining analyticity
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Homework Statement



Determine the set on which f(z) = 1/(z^3 +1) is analytic and compute its derivative.

Homework Equations



Hint: you do not need to appeal to the Cauchy-Riemann equations

The Attempt at a Solution


Total stuck with this one. everything we have done this far has been using the c-r equations.

Thanks for any input.
 
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Ask yourself:

1) Are there any values of z for which f(z) is not defined? If so, what are they, and what does it tell you about the analyticity of the function?

2) When can you treat taking a derivative of a complex function ##\frac{df(z)}{dz}## just like taking a derivative of a real function?
 
Are the function and derivatives defined everywhere?
 

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