input newcourbes; input couleur; input geometriesyr16; input TEX; verbatimtex %&latex \documentclass{article} \usepackage[upright]{fourier} \usepackage{color} \def\E{\mathrm{e}} \let\ve\vec \def\DR{\mathcal{D}} \def\CR{\mathcal{C}} \newcommand{\Mathbold}[1]{\mbox{\boldmath$#1$\unboldmath}} \begin{document} etex %%%%%%%%%%%%%%%%%%%%%%%%%%%% %% réciproque %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% beginfig(1) vardef fx(expr t)= t enddef; vardef fy(expr t)= exp(t-1)-t enddef; repere(0,0,-1,4,-3,4,2cm,2cm); r_axes; r_origine; r_unites; r_labelxy; path g,h; g:= f_courbe(fx,fy,1,4,100); draw g withcolor red; draw g reflectedabout ((0,0),r_p(3,3)) withcolor blue; draw r_droite(0,0,1) dashed evenly; pair n; n:=r_p(2,fy(2)); label.lrt(btex $y=f(x)=\E^{x-1}-x$ etex,n ) withcolor red; label.lrt(btex $y=f^{-1}(x)$ etex,n reflectedabout ((0,0),r_p(3,3)) ) withcolor blue; label.lrt(btex $y=x$ etex, r_p(-2,-2)); r_fin; endfig; %%%%% % approximation discrète d'une edo %%%%%%%%%%%%%%%%%%%%%%%% beginfig(2) repere(0,0,-1,10,-1,5,1cm,1cm); r_axenom(btex $t$ etex,btex $u$ etex); r_origine; vardef fx(expr t)=t enddef; vardef fy(expr t)=sqrt(t+1) enddef; draw f_courbe(fx,fy,0,8,100) withpen pencircle scaled 1.3bp withcolor .6white; numeric v; pair uz, uu, ud, ut,Uu,Ud,Ut,Uq,tu,td,tt; uz:=r_p(0,fy(0));r_pp(0,fy(0)); uu:=r_p(2,fy(2));tu:=r_p(2,0); ud:=r_p(4,fy(4));td:=r_p(4,0); ut:=r_p(6,fy(6));tt:=r_p(6,0); v:=1; Uu:=r_p(2,fy(2)+.7v);r_pp(2,fy(2)+.7v); Ud:=r_p(4,fy(4)+v);r_pp(4,fy(4)+v); Ut:=r_p(6,fy(6)+v);r_pp(6,fy(6)+v); Uq:=r_p(8,fy(8)+.9v);r_pp(7.5,fy(7.5)+.9v); draw Uu--tu dashed evenly; draw Ud--td dashed evenly; draw Ut--tt dashed evenly; r_cp(2,fy(2));r_cp(4,fy(4));r_cp(6,fy(6)); draw uz--Uu--Ud--Ut--Uq; draw (Uu shifted r_p(.1v,.3v))--(Ud shifted r_p(-0.2v,.18v)) dashed withdots withpen pencircle scaled 2bp; draw (tu shifted r_p(0.1v,-.3v))--(td shifted r_p(-0.1v,-.3v)) dashed withdots withpen pencircle scaled 2bp; drawdblarrow (td shifted r_p(0,-v))--(tt shifted r_p(0,-v)); label.lrt(btex $u(t_n)$ etex, ud); label.lrt(btex $u(t_{n+1})$ etex, ut); label.top(btex $u_n$ etex, Ud); label.top(btex $u_{n+1}$ etex, Ut); label.ulft(btex $u_1$ etex, Uu); label.lft(btex $u_0$ etex, uz); label.lrt(btex $t_n$ etex, td); label.llft(btex $t_1$ etex, tu); label.bot(btex $t_{n+1}$ etex, tt); label.top(btex $h$ etex, .5(td+tt) shifted r_p(0,-v)); label.top(btex {\small Solution numérique} etex, Uq); label.top(btex {\small Solution exacte} etex, r_p(8,fy(8))) withcolor 0.6white; r_fin; endfig; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % M E T H O D E D e S T R A P E Z E S % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Déclarations des constantes % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% numeric xmin, xmax, ymin, ymax, N; ux:=1cm; uy:=1cm; xmin := -.5 ; xmax := 8; ymin := -.5; ymax := 4; pair d,h; d:=(.1*ux,0); h:=(0,.1*uy); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Définitions des axes et labels associés %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% vardef axes = drawarrow (ux*xmin,0) -- (ux*xmax,0) ; % axe des x drawarrow (0,uy*ymin) -- (0,uy*ymax); % axe des y label.rt(btex $t$ etex,(xmax*ux,0)); % label de l'axe des x label.urt(btex $u$ etex,(0,ymax*uy)); % label de l'axe des y enddef; beginfig(3); path t; % tirets t:=((0,0)shifted h)--((0,0)shifted -h); pair A,B,C,a,b; A:=(ux,1.5*uy); C:=(2.5*ux,2.5*uy); B:=(7*ux,uy); a:=A yscaled 0; b:=B yscaled 0; pair M,N,m,n; path P,Q,QQ,R,S; P:=A{dir-10}..C..{dir-10}B; M:=point .7 of P; N:=point 1.2 of P; m:=M yscaled 0; n:=N yscaled 0; S:=subpath(.7,1.2) of P; QQ:=M--N; Q:=N--n--m--M--cycle; R:=buildcycle(S,QQ); fill R withcolor bleu_f; fill Q withcolor bleu; axes; draw P; draw (A--a) dashed evenly; draw (B--b) dashed evenly; draw (M--m) dashed evenly; draw (N--n) dashed evenly; draw t shifted a; draw t shifted b; draw t shifted m; draw t shifted n; label.bot(btex $kh$ etex,m shifted -1.9h-d); label.bot(btex $(k+1)h$ etex,n shifted -h+4d); pair T; T:=M xscaled 0; draw (T--M) dashed evenly; pair TT; TT:=N xscaled 0; draw (TT--N) dashed evenly; path U,V; pair t; U:=N--n; V:=T--(T shifted (6*ux,0)); t:=U intersectionpoint V; draw (T shifted d)--(T shifted -d); label.lft(btex $u(kh)=u_k$ etex,T shifted -d); draw (TT shifted d)--(TT shifted -d); label.lft(btex $u((k+1)h)=u_{k+1}$ etex,TT shifted -d); endfig; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % Méthode de Newton % % beginfig( 4) %%%%%%%%%%%%%%%%%%%%%%% vardef fx(expr t)= t enddef; vardef fy(expr t)= (t-1)**2 % c'est la seule ligne à changer enddef; %%%%%%%%%%%%%%%%%%%%% repere(0,0,-.5,4,-2,5,3cm,1cm); r_axes; draw f_courbe(fx,fy,-.5,4,100)withpen pencircle scaled 1.5bp withcolor blue; draw f_tangente(fx,fy,2,0.05); dotlabel.top( btex etex, r_p(2,1) ); dotlabel.top( btex etex, r_p(2,0) ); dotlabel.top( btex etex, r_p(1.5,0) ); dotlabel.top( btex etex, r_p(1,0) ); draw r_segment(2,1,2,0) dashed evenly; drawarrow r_p(1.5,-1.5)--r_p(1.5,-0.2) withcolor .7white; drawarrow r_p(2,-1)--r_p(2,-0.1) withcolor .7white; drawarrow r_p(.5,1)--r_p(1,0.1) withcolor .7white; label.bot(btex $x_1$ etex,r_p(1.5,-1.5) )withcolor .7white; label.bot(btex $x_0$ etex,r_p(2,-1) )withcolor .7white; label.top(btex Le zéro cherché etex,r_p(.5,1) )withcolor .7white; r_fin; endfig; end