/* -*-ePiX-*- */
#include "epix.h"
#include "cme_style.h"
using namespace ePiX;

double mx(0.5), my(0.33), dx(0.05), x1(mx - dx), x2(mx + dx);

double f(double x)
{
  return sqrt((1 - x)*(1+x));
}

double MAX(1.1);

int main()
{
  picture(P(-MAX,-MAX), P(MAX,MAX), "2 x 2in");

  begin();
  arrow_inset(0.75);
  arrow_ratio(1.5);
  arrow_width(5);

  cme_dashed();
  line(P(mx, 0), P(mx, f(mx)));
  cme_solid();

  arrow(P(mx - 3*dx, my), P(mx - dx, my));
  arrow(P(mx + 3*dx, my), P(mx + dx, my));

  label(P(x1, 0.66*f(x1)), P(-4,0), "$dx$", l);
  label(P(x2, 0.66*f(x2)), P(4,0), "$y$", r);

  smallbrace(P(mx,0), P(0,0), "$x$");

  cme_bold();
  circle();
  line(P(x1, -f(x1)), P(x1, f(x1)));
  line(P(x2, -f(x2)), P(x2, f(x2)));

  label(P(0,0), P(-2,-2), "$O$", bl);
  label(P(xmax(),0), P(2,-2), "$x$", br);
  label(P(0,ymax()), P(-2,2), "$y$", tl);

  line(P(xmin(), 0), P(xmax(), 0), 10);
  line(P(0, ymin()), P(0, ymax()), 10);

  caption("Fig.~62.", P(0,12));
  tikz_format();
  end();
}