deletions | additions       diff --git a/Random.tex b/Random.tex  index 5c08b89..466f9ad 100644  --- a/Random.tex  +++ b/Random.tex 
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Is \begin{equation}  \sum_i={-\infty}^\infty \sum_{i=-\infty}^{\infty}  f(x_i)\prod_{j=-\infty}^\infty\frac{x-x_j}{x_i-x_j} = cos(x) \end{equation}  For $f(x)=x$, $x_i=(-1)^i\pi$