program prog1010
      
      implicit none

      real x,t,tfinal,dt,f,xe

      open(file="data.d",13)
      tfinal = 10
      dt = 0.05
      x = 1

      do 10 t=0,tfinal,dt
         f = sin(2*t) - x
         x = x + (f)*dt
         xe = 7.0/5.0*exp(-(t+dt)) + 1.0/5.0*sin(2*(t+dt)) 
     c    - 2.0/5.0*cos(2*(t+dt))
         write(13,*) t+dt,x,xe,xe - x
 10   continue

      close(13)
      stop
      end