Help with found Fourier complex series of e^t

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SUMMARY

The discussion centers on finding the Fourier coefficients \( c_n \) for the function \( f(t) = e^t \) using the Fourier series representation \( f(t) = \sum C_n e^{int} \). The coefficients are calculated using the integral formula \( \frac{1}{2\pi} \int_{-\pi}^{\pi} f(t) e^{int} dt \). Participants emphasize that \( e^t \) is not periodic over the entire real line, suggesting a specific interval for the Fourier series. Additionally, they recommend solving the integral directly rather than employing integration by parts, which is deemed unnecessary.

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needved
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Homework Statement


i have this function
\begin{equation}
f(t) = e^t
\end{equation}

Homework Equations


[/B]
the Fourier seria have the form
\begin{equation}
f(t) = \sum C_{n} e^{int}
\end{equation}

The Attempt at a Solution

}
[/B]
so i need to find the coeficients $c_{n}$ given by
\begin{equation}
\frac{1}{2\pi} \int_{-\pi}^{\pi} f(t) e^{int} dt
\end{equation}

my attempts are try to find the coeficients doing integration by parts but i don't have anithing. Any help here please.

thanks in advance
 
Last edited:
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needved said:

Homework Statement


i have this function
\begin{equation}
f(t) = e^t
\end{equation}

Homework Equations


[/B]
the Fourier seria have the form
\begin{equation}
f(t) = \sum C_{n} e^{int}
\end{equation}

The Attempt at a Solution

}
[/B]
so i need to find the coeficients $c_{n}$ given by
\begin{equation}
\frac{1}{2\pi} \int f(t) e^{int} dt
\end{equation}

my attempts are try to find the coeficients doing integration by parts but i don't have anithing. Any help here please.

thanks in advance

(1)What is the interval over which you want the Fourier series? The series produces a periodic function of ##t##, but ##e^t## is not periodic on the whole line.
(2) You have an elementary integral that you ought to be able to solve almost by inspection. No fancy integration tools are needed, and certainly integration by parts is overkill.
 

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