# Calculus Quiz

Calculus Level 5

$f(x)=\sum_{k=1}^{\infty}\frac{\sin(kx)}{k^2}$

Find the value of $$x$$, with $$0< x\leq 2\pi$$, where $$f(x)$$ attains its maximal value. Write $$x=\frac{a\pi}{b}$$, where $$a$$ and $$b$$ are coprime positive integers, and enter $$a+b$$.

If you come to the conclusion that no such $$x$$ exists, enter 666.

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