# Trignometry+Summation

Calculus Level 5

The sum $$\displaystyle \sum _{ n=1 }^{ 50 }{ \tan ^{ -1 }{ \left( \frac { 2n }{ { n }^{ 4 }-{ n }^{ 2 }+1 } \right) } }$$ can be expressed as $$\tan^{-1} k$$.
Find the value of $$k$$.

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