Latex pgfplots cannot show the line

I am trying to plot a graph like this in Latex:
It turns out to be looking like this with out a line:

This is my tex file

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{pgfplots}
\pgfplotsset{compat=1.5}

\begin{document}
\begin{center}
\begin{tikzpicture}
\begin{axis}[
    axis lines = left,
    ytick={0,0.25},
    xtick={0,2,4,6,8,10},
    height=5.5cm,
    width=13cm,
    xmax=10,
    ymax=0.25,
    ymin=0,
    xmin=0,
    xlabel = T,
    ylabel = k,
]

\addplot [
    domain=0:100, 
    samples=1000, 
    color=blue,
    ]
    {0.001^(x/x+1) * (1+x)};
\addlegendentry{\(T=p^{\frac{k}{k+1}(k+1)}\)}

\end{axis}
\end{tikzpicture}
\end{center}

\end{document}

Have I done any thing wrong? Thank you.

Simple math problem: (x/x+1) != (x/(x+1))

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{pgfplots}
\pgfplotsset{compat=1.5}

\begin{document}
\begin{center}
\begin{tikzpicture}
\begin{axis}[
    axis lines = left,
    height=5.5cm,
    width=13cm,
    xlabel = T,
    ylabel = k,
]

\addplot [
    domain=0:10, 
    samples=100, 
    color=blue,
    ]
    { (1+x)*0.001^(x/(x+1)) };
\addlegendentry{\(T=p^{\frac{k}{k+1}}(k+1)\)}

\end{axis}
\end{tikzpicture}
\end{center}

\end{document}