If y=tan−111+x+x2+tan−11x2+3x+3+tan−11x2+5x+7+⋯+ upto n terms, then y′(0) is equal to
If y=tan−1(11+x+x2)+tan−1(1x2+3x+3)+tan−1(1x2+5x+7)+⋯⋯⋯ n terms, then y'(0) is