Cauchy–Riemann equations

These two partial differential equations give the condition a complex function f = u + iv must satisfy to be holomorphic (complex differentiable). They are used to test holomorphy and in complex analysis generally.

\begin{aligned}\frac{\partial u}{\partial x}&=\frac{\partial v}{\partial y}\\\frac{\partial u}{\partial y}&=-\frac{\partial v}{\partial x}\end{aligned}

What the symbols mean

real part of the complex variable z = x + iy
imaginary part of the complex variable z = x + iy
real part of the function f = u + iv
imaginary part of the function f = u + iv

About this formula

  • FieldMathematics
  • TopicComplex analysis
  • LevelUniversity
  • Also calledCauchy-Riemann conditions, d'Alembert–Euler conditions, Cauchy–Riemann conditions
  • SourceWikidata Q622741

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