Program eq2

implicit none
real :: a,b,c,d,x1,x2,xi1,xi2

write(6,*) ' Equazione 2° grado: dammi a,b,c'
read(5,*) a,b,c

d=b**2-4*a*c

if(d >= 0) then
   x1=(-b-sqrt(d))/(2*a)
   x2=(-b+sqrt(d))/(2*a)
   write(6,*) "x1=", x1
   write(6,*) "x2=", x2
else
   x1=-b/(2*a)
   x2=x1
   xi1=-sqrt(-d)/(2*a)
   xi2=sqrt(-d)/(2*a)
   write(6,*) 'x1= (', x1, ',' , xi1,')'
   write(6,*) 'x2= (', x2, ',' , xi2,')'
endif
end