MHB How to Expand cx(x-l) into a Fourier Series?

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The function cx(x-l) is proposed for expansion into a Fourier series of the form Σ a_n e^(-α_n x). There is confusion regarding the term α, with suggestions that it should depend on n for proper Fourier series representation. The discussion indicates that cx(x-l) can be transformed into a series involving complex exponentials. A specific example is provided, showing a potential expansion with constants and exponential terms. The conversation highlights the need for clarity in defining parameters for accurate series representation.
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I have a function $$cx(x-l)$$ where c is constant

I want to expansion this function $$cx(x-l)$$ to $$\sum_{n=-\infty}^{\infty}a_{n}e^{-\alpha x}$$

how can i do it? you have a idea
 
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Is there perhaps a typo in the summand? The exponential does not seem to depend on $n$ and it is not clear to me what $\alpha$ is.
 
Janssens said:
Is there perhaps a typo in the summand? The exponential does not seem to depend on $n$ and it is not clear to me what $\alpha$ is.


$$cx(x-l)$$ to $$\sum_{n=-\infty}^{\infty}a_{n}e^{-\alpha_{n} x}$$ $\alpha$ is constant any constant
 
Another said:
$$cx(x-l)$$ to $$\sum_{n=-\infty}^{\infty}a_{n}e^{-\alpha_{n} x}$$ $\alpha$ is constant any constant

That looks like a Fourier series transform.

We have:
$$cx(x-1) = c\left(\frac{\pi^2}3 + (-2-i)e^{-ix} - (2-i)e^{ix} + ...\right)$$
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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