# It is impossible

Discrete Mathematics Level 4

$\large L=\displaystyle\lim_{x \to -1}\dfrac{\displaystyle\prod_{r=1}^{4n}(1+(-1)^{r+1}x^r)}{\displaystyle\prod_{r=1}^{2n}(1+(-1)^{r+1}x^r)^2}$

Find the value of $$L$$. 

Notation: $$\dbinom MN$$ denotes the binomial coefficient, $$\dbinom MN = \dfrac{M!}{N!(M-N)!}$$.

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