\(\sqrt{1+x^2+\frac{x^2}{\left(x+1\right)^2}}+\frac{1}{x+1}\)
\(=\sqrt{x^2+2x+1-2x+\frac{x^2}{\left(x+1\right)^2}}+\frac{1}{x+1}\)
\(=\sqrt{\left(x+1\right)^2-2x+\left(\frac{x}{x+1}\right)^2}+\frac{1}{x+1}\)
\(=\sqrt{\left(x+1-\frac{x}{x+1}\right)^2}+\frac{1}{x+1}\)
\(=x+1-\frac{x}{x+1}+\frac{1}{x+1}\)
\(=\frac{x^2+2x+1-x+1}{x+1}\)
\(=\frac{x^2+x+2}{x+1}\)