\input fig4tex.tex
%%% debut dessin
%%%%%%%%%%%%%%%%%%%%%%%
% pts caracteristiques
%%%%%%%%%%%%%%%%%%%%%%
\figinit{cm}
% pt de controle de Bezier
\figpt 1:(0,0)\figpt 2:(1,-1)\figpt 3:(2,1)\figpt 4:(3,3)
\figpt 5:(0,1.25)
%% pt sur la courbe
\figptBezier 5::0.25[1,2,3,4]\figptBezier 6::0.8[1,2,3,4]
%% pt pour definir la secante
\figptbaryR 7:[5,6;-0.3,1]\figptbaryR 8:[5,6;1,-0.3]
%%% vecteur tangent a la courbe en A
\figvectDBezier 9:1,0.25[1,2,3,4]
% pt translate de A dans la direction tangente a la courbe
\figpttra 10: = 5/1.2,9/
\figpttra 11: = 5/-0.3,9/
% point pour les axes
\figpt 12:(-1.5,-1.5)\figpt 13:(3.5,-1.5)
\figpt 14:(-1.5,-1.5)\figpt 15:(-1.5,3.5)
% point a et a+h
\figvectC 16(0,1)\figvectC 17(1,0)
\figptinterlines 18:[5,16;12,17]
\figptinterlines 19:[5,17;14,16]
\figptinterlines 20:[6,16;12,17]
\figptinterlines 21:[6,17;14,16]
% fleche
%\figgetdist\AM[5,10]
%%%%%%%%%%%%%%
% fichier ps
%%%%%%%%%%%%%
\psbeginfig{}
\psline[10,11]\psline[7,8]\psarrow[12,13]\psarrow[14,15]
\pssetdash{5}\psline[18,5,19]\psline[20,6,21]\pssetdash{\defaultdash}
\pssetwidth{1}\psBezier 1[1,2,3,4]\pssetwidth{\defaultwidth}
\pssetarrowheadfill{yes}
\psarrowcircP 5;-3.5[7,10]
\psendfig
%%%
% writing
\figvisu{\figBoxA}{}{
\figwritese 10:$\Delta$(0.1)
\figwritese 7:$\Delta_h$(0.1)
\figsetmark{$\bullet$}
\figwritese 6:$M$(0.1)
\figwritese 5:$A$(0.1)
\figwrites 18:$a$(0.2)
\figwritew 19:$f{(}a{)}$(0.1)
\figwrites 20:$a+h$(0.1)
\figwritew 21:$f{(}a+h{)}$(0.1)
}
%%%%
\smallskip\centerline{\box\figBoxA}\smallskip
\bye