\documentclass{standalone} \usepackage{luamplib} \begin{document} \mplibtextextlabel{enable} \begin{mplibcode} beginfig(1); numeric minx, maxx, s, u, v; minx = 13/8; s = 1/16; maxx = 19/4; u = 89; v = 3072; def f(expr x) = 1/256 mlog(x) / x enddef; path ff, xx, yy; ff = for x=minx step s until maxx-s: (x, f(x)) .. endfor (maxx, f(maxx)); ff := ff xscaled u yscaled v; xx = origin -- right scaled (maxx-minx) scaled u; yy = origin -- up scaled 0.09v; xx := xx shifted point 0 of ff shifted 20 down; yy := yy shifted point 0 of ff shifted 20 left; numeric pi, e, fpi, fe; pi = 3.141592653589793 u; fpi = f(3.141592653589793) * v; e = 2.718281828459045 u; fe = f(2.718281828459045) * v; path ee, pp; ee = (e, ypart point 0 of xx) -- (e, fe) -- (xpart point 0 of yy, fe); pp = (pi, ypart point 0 of xx) -- (pi, fpi) -- (xpart point 0 of yy, fpi); draw ee dashed withdots scaled 1/4 withcolor 2/3 red; draw pp dashed withdots scaled 1/2 withcolor 2/3 red; draw ff withcolor 3/4 blue; drawarrow xx; drawarrow yy; for x=2 upto 4: draw (down--up) scaled 2 shifted (x * u, ypart point 0 of xx); label.bot("$" & decimal x & "$", (x * u, ypart point 0 of xx - 2)); endfor for y=31 upto 38: draw (left--right) scaled 2 shifted (xpart point 0 of yy, y/100*v); endfor for y=32, 35, 38: label.lft("$" & decimal (y/100) & "$", (xpart point 0 of yy-2, y/100*v)); endfor drawoptions(withcolor 1/2 red); label.bot("$e$", point 0 of ee shifted 4 down); label.lft("$1/e$", point 2 of ee shifted 2 left); label.bot("$\pi$", point 0 of pp shifted 4 down); label.lft("$\ln\pi/\pi$", point 2 of pp shifted 2 left); drawoptions(withcolor 2/3 blue); label.urt("$\displaystyle y={\ln x\over x}$", point 42 of ff); drawoptions(); label.rt("$x$", point 1 of xx); label.top("$y$", point 1 of yy); label("\dots\ hence\enspace $e^\pi > \pi^e$.", (4u, 0.38v)); endfig; \end{mplibcode} \end{document}