Reduce complex exponential expression

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SUMMARY

The discussion focuses on proving the equation 1 - exp(-iwt) = 2i*sin(wt/2). Participants initially questioned the validity of the equation, noting discrepancies when substituting specific values for wt. Ultimately, it was clarified that the correct expression involves exp(-iwt/2), leading to the successful proof of the equivalence. This highlights the importance of careful manipulation of exponential and trigonometric identities in complex analysis.

PREREQUISITES
  • Understanding of complex exponential functions, specifically exp(iwt)
  • Knowledge of trigonometric identities, particularly sin and cos functions
  • Familiarity with Euler's formula: exp(iθ) = cos(θ) + i*sin(θ)
  • Basic skills in manipulating algebraic expressions involving complex numbers
NEXT STEPS
  • Study the derivation and applications of Euler's formula in complex analysis
  • Learn about the properties of complex exponential functions and their graphical representations
  • Explore advanced trigonometric identities and their proofs
  • Investigate the implications of complex numbers in physics, particularly in wave mechanics
USEFUL FOR

Students of mathematics, particularly those studying complex analysis, as well as educators and anyone involved in teaching or learning about trigonometric identities and complex functions.

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Homework Statement



prove that:
1-exp(-iwt)= 2i*sin(wt/2)

Homework Equations



exp(iwt)= cos (wt) + i*sin(wt)

The Attempt at a Solution



I attempted to express the exponential into sum of cos and sin and considering t=2*t/2 in order to obtain an argument like (t/2) (using duplication expression of trigonometry theory).


Thanks in advance
 
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You must have the problem wrong, because the equation you are trying to prove is not true. For example, if wt = pi/2, then the left-hand side is equal to 1+i and the right-hand side is equal to √2 * i.
 
Yes, you're right and the problem was wrong.
In the right-hand side of first expression, there's also

exp(-iwt/2)

And the equivalence is proved.
 
Last edited:

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