How Does the Conjugate of e^(it) Extend to e^(-it)?

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SUMMARY

The discussion centers on the relationship between the conjugate of the complex exponential function and its representation on the unit circle. The user correctly identifies that the conjugate of \( e^{it} \) is \( e^{-it} \), which can be expressed as \( \cos(t) - i\sin(t) \). This conclusion is supported by the properties of cosine and sine functions, where cosine is even and sine is odd. Thus, the equation \( \cos(t) - i\sin(t) = e^{-it} \) is established as true.

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  • Understanding of complex numbers and their properties
  • Familiarity with Euler's formula \( e^{it} = \cos(t) + i\sin(t) \)
  • Knowledge of trigonometric functions, specifically the even and odd properties of sine and cosine
  • Basic understanding of the unit circle in the complex plane
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Dissonance in E
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Hi I have a parametrisation of the unit circle
z = cos(t) + isin(t) = e^(it)
now i guess that the conjugate of that is the same but with a negative coefficient on the imaginary part, namely:
conj z = cos(t) - isin(t)
How does that extend to the e^(it) form? is the following true:
cos(t) - isin(t) = e^(-it)

Thanks
 
Last edited:
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[tex]e^{-it}=\cos(-t)+i\sin(-t)[/tex]. cosine is an even function, an sine is an odd function, so

[tex]e^{-it}=\cos(t)-i\sin(t)[/tex]
 
nice, thanks.
 

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