Fourier Transform: Steps to Find the Solution for Given Functions

myth_kill
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Homework Statement



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Homework Equations



i cannot start with the q



The Attempt at a Solution



how to find the Fourier transform of the given function?

i don't want the MATLAB code, i want to know how to actually find the Fourier transform of this function
 
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for starters as its an even function you only need consider cosine terms, and as its periodic only terms with an integer multiple of period will constribute so you will end up with an infinite sum something like
f(x) = \sum_n a_n cos(\frac{n \pi x}{ L})

to find each coefficient, find the integral over a period of the function multiplied by the corresponding cosine component. This works as the functions are all orthogonal to each other
 
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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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