Identify the value of ∑k=1narctan(1k2+k+1)\sum_{k=1}^n \arctan(\frac{1}{k^2+k+1})∑k=1narctan(k2+k+11).
arctan(n)\arctan(n)arctan(n)
arctan(n+1)−π/4\arctan(n+1) - \pi/4arctan(n+1)−π/4
arctan(n+1)\arctan(n+1)arctan(n+1)
arctan(n/(n+1))\arctan(n/(n+1))arctan(n/(n+1))