cauchy riemann equations

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CAUCHY-RIEMANN EQUATION Hanpen Robot

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CAUCHY-RIEMANNEQUATION

Hanpen Robot

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic β‡’πœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=πœ•π‘“

πœ•π‘₯

πœ•π‘₯

πœ• 𝑧+πœ•π‘“

πœ•π‘¦

πœ•π‘¦

πœ• 𝑧

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=πœ•π‘“

πœ•π‘₯

πœ•π‘₯

πœ• 𝑧+πœ•π‘“

πœ•π‘¦

πœ•π‘¦

πœ• 𝑧

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=πœ•π‘“

πœ•π‘₯

πœ•π‘₯

πœ• 𝑧+πœ•π‘“

πœ•π‘¦

πœ•π‘¦

πœ• 𝑧

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=πœ•π‘“

πœ•π‘₯

1

2+πœ•π‘“

πœ•π‘¦

𝑖

2

∴ π‘₯ =𝑧 + 𝑧

2, 𝑦 =

𝑧 βˆ’ 𝑧

2𝑖

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=πœ•π‘“

πœ•π‘₯

1

2+πœ•π‘“

πœ•π‘¦

𝑖

2

∴ π‘₯ =𝑧 + 𝑧

2, 𝑦 =

𝑧 βˆ’ 𝑧

2𝑖

Cauchy-Riemann Equation

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦

∴ π‘₯ =𝑧 + 𝑧

2, 𝑦 =

𝑧 βˆ’ 𝑧

2𝑖

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

⇕

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦=1

2

πœ•π‘“

π‘–πœ•π‘¦+ 𝑖

πœ•π‘“

πœ•π‘¦= 0

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

⇕

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦=1

2

πœ•π‘“

π‘–πœ•π‘¦+ 𝑖

πœ•π‘“

πœ•π‘¦= 0

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

⇕

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦=1

2

πœ•π‘“

π‘–πœ•π‘¦+ 𝑖

πœ•π‘“

πœ•π‘¦= 0

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

⇕

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦=1

2

πœ•π‘“

π‘–πœ•π‘¦+ 𝑖

πœ•π‘“

πœ•π‘¦= 0

Cauchy-Riemann Equation

𝑓 𝑧 is holomorphic βŸΊπœ•π‘“

πœ•π‘₯=

πœ•π‘“

π‘–πœ•y

⇕

πœ•π‘“

πœ• 𝑧=1

2

πœ•π‘“

πœ•π‘₯+ 𝑖

πœ•π‘“

πœ•π‘¦=1

2βˆ’π‘–

πœ•π‘“

πœ•π‘¦+ 𝑖

πœ•π‘“

πœ•π‘¦= 0

Cauchy-Riemann Equation

∴ 𝑓 𝑧 is holomorphic β‡”πœ•π‘“

πœ• 𝑧= 0

π‘‰π‘’π‘Ÿπ‘¦ π‘ π‘–π‘šπ‘π‘™π‘’!

Cauchy-Riemann Equation

∴ 𝑓 𝑧 is holomorphic β‡”πœ•π‘“

πœ• 𝑧= 0

π‘‰π‘’π‘Ÿπ‘¦ π‘ π‘–π‘šπ‘π‘™π‘’!

Exercise

Is 𝑧 3 holomorphic function?

Answer

𝑓 𝑧 = 𝑧 3 = 𝑧 𝑧32 β‡’

πœ•π‘“

πœ• 𝑧=3

2𝑧32 𝑧 β‰  0

∴ 𝑧 3 is not holomorphic function.

Exercise

Is 𝑧 3 holomorphic function?

Answer

𝑓 𝑧 = 𝑧 3 = 𝑧 𝑧32 β‡’

πœ•π‘“

πœ• 𝑧=3

2𝑧32 𝑧 β‰  0

∴ 𝑧 3 is not holomorphic function.

Exercise

Is 𝑧 3 holomorphic function?

Answer

𝑓 𝑧 = 𝑧 3 = 𝑧 𝑧32 β‡’

πœ•π‘“

πœ• 𝑧=3

2𝑧32 𝑧 β‰  0

∴ 𝑧 3 is not holomorphic function.

Exercise

Is 𝑧 3 holomorphic function?

Answer

𝑓 𝑧 = 𝑧 3 = 𝑧 𝑧32 β‡’

πœ•π‘“

πœ• 𝑧=3

2𝑧32 𝑧 β‰  0

∴ 𝑧 3 is not holomorphic function.

END