Plot a curve using the tikz package

I am trying to plot the curve shown in the following picture below.

Is there a someone who can help me to draw the picture using TikZ or PSTricks.

• You will need to give some more informations about what you're struggling with. It's a pretty straightforward drawing, bur unfortunately, without knowing exactly what it is supposed to picture, it's hard to help. What have you already tried? Jan 5 at 16:31
• The TikZ manual (see CTAN, or texdoc.org/serve/tikz/0) starts off with some tutorials, if you study chapter 2 of the manual that will help you drawing something like that. Jan 5 at 16:35
• I would recommend you use tikz. To draw a blue line, with an arrow between coordiantes (a,b) and (c,d) you can use \begin{tikzpicture} \draw [blue, ->] (a,b) -- (c,d); \end{tikzpicture}. If you don't want the arrow, don't specify -> in the options. To complete your picture just add more \draw commands with the appropriate coordinates. Hopefully, this is enough to get you started. If you get stuck with a specfic problem, please post a question and include a MWE showing what you have tried so far or how far you got with your drawing. Jan 5 at 17:19

If you know the functions of your plots your best option would be pgfplots:

\documentclass[border=1cm]{standalone}

\usepackage{tikz,pgfplots}
\pgfplotsset{compat=1.12}
\usepackage{upgreek}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
axis lines=middle,
xlabel=$\uptau 1$,
every axis x label/.style={at={(current axis.right of origin)},anchor=west},
ylabel=$\uptau 2$,
every axis y label/.style={at={(current axis.above origin)},anchor=south},
xmin=-0.5,
xmax=10.5,
ymin=-30,
ymax=5,
yticklabels={,,}, % removes ticklabels from y axis
ytick style={draw=none}, % removes ticks from y axis
xticklabels={,,}, % removes ticklabels from y axis
xtick style={draw=none} % removes ticks from y axis
]
\addplot+[orange,no marks,domain=-1:10,samples=100, thick] {(-x/2)+1} node[midway,yshift=0.5cm] {$f1 (\uptau 1)$};
\addplot+[blue,no marks,domain=-1:10,samples=100, thick] {(-x/2)-10} node[midway,yshift=0.5cm] {$f2 (\uptau 2)$};
\end{axis}

\end{tikzpicture}

\end{document}