# Just try

Calculus Level pending

On the interval $$-\pi \leq x \leq \pi$$, $$x^2$$ can be expressed as an infinite sum of cosines, in the following form:

$\large x^2= \dfrac{\pi^a}{b} +4 \sum_{n=1}^{\infty} (-1)^n \dfrac{\cos nx}{n^c}$

Find $$a+b+c$$

Clarification: $$a, b, c$$ are constants.

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