TOL = 1E-6;
deff("y = fn(x)","y =  x - 0.2*sin(x) - 0.5") 
xg = input("abscisse gauche: "); 
xd = input("abscisse droite: ");
fg = fn(xg); fd = fn(xd); fm = (fg+fd)/2;
while(abs(fm) > TOL) 
    xm = xg - fg*(xg-xd)/(fg-fd);
    fm = fn(xm);
    if(fm*fg <	0)
      xd = xm; fd = fm;
    else
       xg = xm; fg = fm;
    end
end
xm = xg - fg*(xd-xg)/(fd-fg);
temp = [xm,fn(xm)];
mprintf("\n%12.6f\t%12.6f\t\n",temp);