\documentclass[border=5mm]{standalone} \usepackage{luamplib} \begin{document} \mplibtextextlabel{enable} \begin{mplibcode} beginfig(1); path Y, L, C, P, S; % cycloid numeric r, s; r = 160; def sin(expr x) = sind( 57.29577951308232 x) enddef; def cos(expr x) = cosd( 57.29577951308232 x) enddef; vardef u(expr x) = x - sin(x) enddef; vardef v(expr x) = 1 - cos(x) enddef; vardef f(expr t) = u(t) < v(t) enddef; tolerance := epsilon; numeric a; a = solve f(2,3); Y = (origin for t = 1 upto 128: -- (u(t / 128 * a), -v(t / 128 * a)) endfor) scaled r; % Y = origin for t=5 step 5 until 140: % -- (0, r) rotated t shifted (t / 57.29577951308232 * r, -r) % endfor cutafter (origin -- 4r * dir -45); z0 = point 0 of Y; z1 = point infinity of Y; % line L = z0 -- z1; % circle C = quartercircle rotated 180 scaled 2x1 shifted (x1, y0); % parabola f = x^2, f' = 2x P = z0{1,-2} ... (xpart 1/2[z1, z0], ypart 1/4[z1, z0]){1,-1} ... z1 {1, 0}; % sixth degree f = x^6, f' = 6x^5 S = z0{1,-6} ... (xpart 1/2[z1, z0], ypart 1/64[z1, z0]){1, -6/32} ... z1 {1, 0}; % axes draw z0 -- (x0,y1) -- z1 withcolor 3/4; drawoptions(withcolor 2/3 red); draw L; dotlabel.urt("Line", point 1/4 of L); drawoptions(withcolor 1/2 green); draw C; dotlabel.urt("Circle", point 1 of C); drawoptions(withcolor 1/4[red, green]); draw P; dotlabel.urt("Parabola", point 1/2 of P); drawoptions(withcolor 3/4[red, green]); draw S; dotlabel.llft("Sixth degree", point 3/4 of S); drawoptions(withcolor 1/2 blue); draw Y; dotlabel.urt("Cycloid", point 100 of Y); drawoptions(); dotlabel.ulft("$A$", z0); dotlabel.urt("$B$", z1); endfig; \end{mplibcode} \end{document}