input geoana.mp
%===========================================================================

verbatimtex 
%&latex 
\documentclass{article} 
\usepackage{palatino} 
\newcommand{\vect}[1]{\overrightarrow{#1}}
\newcommand{\Vect}[1]{\overrightarrow{\strut #1}}
\begin{document} 
etex 
                
beginfig(1); 
path p;
repere(0,0,-2,2,-1,4,1cm,1cm);
r_axes;
r_origine;
grad_x(1); grad_y(1);

p = r_droitedir(0,2,-2);
draw p withcolor blue;

z1=r_point(1.5,-0.5);
z2=r_point(0,2); z3=r_point(1,2); z4=r_point(1,0);
drawarrow z2--z3; drawarrow z3--z4;

label.rt(btex $\Delta$ etex,z1);
label.top(btex $\vect{\imath}$ etex, r_point(0.5,2.1));
label.rt(btex $a \vect{\jmath}$ etex, r_point(1.1,1));

r_fin;
endfig;
end