! 2.8.f90
! $Id: 2.8.f90 1.2 2024/12/07 04:13:47 s Exp $
!
program ex2_8
implicit none
integer :: i
real(8) :: eps,left,mid,right

i=1
eps  =1.0e-5
left =0.0
right=1.0
mid=(left+right)/2.0

do while(abs(f(mid))>eps)
  if(f(mid)>0.0) then
    right=mid
  else
    left=mid
  end if
  mid=(left+right)/2.0
  i=i+1
end do

print *, 'c= ',    mid
print *, 'f(c)= ', f(mid)
print *, 'i= ',    i

stop

contains

function f(x)
  implicit none
  real(8) :: f
  real(8) :: x
  f=-24000.0+6000.0*x+6000.0*x**2+6000.0*x**3+6000.0*x**4+10000.0*x**5
  return
end function f

end program ex2_8
! end