\input{preamble-standalone.ltx} \begin{document} % Ex. No. 23 (Section 7.7 : Demi-tangentes Courbe de Lorentz ) \begin{tikzpicture}[scale=1.25] \tkzInit[xmax=1,ymax=1,xstep=0.1,ystep=0.1] \tkzGrid(0,0)(1,1) \tkzAxeXY \tkzFct[color = red,thick, domain =0:1]{(exp(\x)-1)/(exp(1)-1)} \tkzSetUpPoint[size=6] \tkzDrawTangentLine[draw, kl = 0, kr = 0.4](0) \tkzDrawTangentLine[draw, kl = 0.4,kr = 0 ](1) \tkzText[draw,color = red,fill = orange!20](0.5,0.6)% {$f(x)=\dfrac{\text{e}^x-1}{\text{e}-1}$} \end{tikzpicture} \end{document}