%% auteur : gh

100 setxunit
-.8 3 setxrange
-0.5 3 setyrange

traceaxes
axesarrow
1.7 setlinewidth

/O {0 0} def
16 setfontsize
setTimesItalic
   (O) O dltext
/f {setxvar x 0.75 mul 1 sub 1 x div add} def
/g {setxvar x 0.75 mul 1 sub} def


bleu
1.3 3 {f} Courbe

<tex>
$$ \Gamma $$
</tex>
3 3 [1.5 1.5] ultexlabel

%%<tex>
%%$$ t\to t_0 $$
%%</tex>
%%4.2 4.2 f [1.5 1.5] drtexlabel

0.7 setlinewidth
0.3 1.3 {f} Courbe


1 setlinewidth
rouge
-0.3 7 {g} Courbe

<tex>
$$ y=ax+b $$
</tex>
3 3 g [1.5 1.5] dltexlabel


noir
continu
/xt 2 def
/Mx {xt 0} def
/yt {xt f} def
/zt {xt g} def
/M {xt yt} def
/P {xt zt} def
/My {0 yt} def
/Py {0 zt} def

Mx M (-) line
M My (-) line
P Py (-) line

<tex> 
$$ M(t) $$ 
</tex> 
M [1.5 1.5] ultexlabel

<tex> 
$$ P(t) $$ 
</tex> 
P [1.5 1.5] crtexlabel

<tex> 
$$ x(t) $$ 
</tex> 
Mx [1.5 1.5] dctexlabel

<tex> 
$$ y(t) $$ 
</tex> 
My [1.5 1.5] cltexlabel

<tex> 
$$ ax(t)+b $$ 
</tex> 
Py [1.5 1.5] cltexlabel