 n =70;
 t = linspace ( -1 , 1 , n) ;
k = (1/2)*(cosh(t/2)./((1+(sinh(t/2)).^2)).^(3/2)) ;
 figure
 plot (t ,k ,'b') ;
 axis equal
 title ('Curvatura kappa (t). ') ;
 xlabel('t');
 ylabel('\kappa(t)');
grid on
