function f(x)
! met. Newton
implicit real(8) (a-h, o-z)
common p

!f =exp(x) -p*x*x

!f =exp(x) -3.7*x**1.5

!f =exp(x) -3.7*(x*x)**(1./3.)

!f =exp(x) -3*(x*x)**(1./3.)


! Stationar:
!f =7*x -5*x*cos(x)+3*sin(x)

!f =tan(x)-(8-x)/(x+0.2)

!f =tan(x)-(1.8-x)/(x+0.2)

!f =1.58 +0.99*cos(x) -x

!f =1.58 +0.99*sin(x) -x

!f =x +exp(-p*x*x)*cos(x)

!f =-x +exp(-p*x*x*x)*cos(x)

! f_q
!pi =3.141593
!f =3*(pi+2*x) +5*(pi +2*x)*cos(2*x) - 2*sin(2*x)

! q:
!f =3*x +5*(p+x)*cos(x) -2*sin(x)

! 3-0:
!f =x*x*x*x -5*x*x*x +9*x*x -7*x +2

! 3-1
!f =2 +x*(-7 +x*(9 +x*(-5 +x)))

!f  =1.5 -0.9*cos(x) -0.1*sin(x) +x

! Ozban 2004:
!sin2(x) - x2 + 1 =0; alfa = 1.404491648215341
!f =sin(x)*sin(x) - x*x + 1

! S&S - Ex.3: 2x cos(x) + x - 3; alfa =-3.034664306974045...
!f =2*x*cos(x) +x -3

! S&S - Ex.2: 2.331967655883964
f  =dsqrt(x*x +2*x+5) -2*dsin(x) -x*x +3

! 2014 - 16/I
!f =x +x*x -(sin(x))**2 -1
END
