If y=1/(x+1), then (d^2 y)/(d x^2) at x = 2 is:

$y=\frac{1}{x+1}$

so differentiating y wrt x

$\frac{dy}{d x} = \frac{-1}{(x+1)^2}$

again differentiating wrt x

$\frac{d^2 y}{d x^2} = \frac{2}{(x+1)^3}$

so  $\left.\frac{d^2y}{dx^2}\right]_{x=2} = \frac{2}{(2+1)^3} = \frac{2}{3^3}$

= $\frac{2}{27}$