Proving the Exponential Identity for Complex Numbers

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SUMMARY

The discussion centers on proving the exponential identity for complex numbers, specifically that Exp[z1] * Exp[z2] = Exp[z1 + z2]. The key approach involves using Euler's formula, e^(a + bi) = e^a(cos(b) + i sin(b)), alongside the properties of exponentials and trigonometric identities. The participant expresses confusion regarding the relevance of the binomial theorem to this proof, indicating a need for clarity on the application of these mathematical concepts.

PREREQUISITES
  • Understanding of complex numbers, specifically in the form z = x + iy.
  • Familiarity with Euler's formula: e^(a + bi) = e^a(cos(b) + i sin(b)).
  • Knowledge of exponential functions and their properties.
  • Basic understanding of trigonometric identities, including the addition formulas for sine and cosine.
NEXT STEPS
  • Study the derivation and applications of Euler's formula in complex analysis.
  • Explore the properties of exponential functions, particularly in relation to complex numbers.
  • Learn about trigonometric identities and their proofs, focusing on addition formulas.
  • Investigate the binomial theorem and its applications in complex number proofs.
USEFUL FOR

Students of mathematics, particularly those studying complex analysis, as well as educators looking to clarify concepts related to exponential functions and complex numbers.

rbwang1225
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Homework Statement


Let z=x+iy prove that Exp[z1]*Exp[z2]=Exp[z1+z2]


Homework Equations


Binomial thm (x+y)^n=Sum[Bin[n,k]*x^n-k*y^k,{k,1,n}]


The Attempt at a Solution


I have no idea about this question...

Please give me some help.
 
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I don't see how the binomial theorem has anything to do with this. I think better would be
[tex]e^{a+ bi}= e^a(cos(b)+ i sin(b))[/tex]
together with [itex]e^{x+y}= e^x e^y[/itex], cos(x+y)= cos(x)cos(y)- sin(x)sin(y), and sin(x+y)= sin(x)cos(y)+ cos(x)sin(y).
 
The hint was given by my teacher, but I think he is a little unreliable.
 

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