Equation_solver_fortran.f90

PROGRAM Equation_solver_fortran
  ! This is program calculate the real roots of second order equation
  IMPLICIT NONE ! this is important to get used to this statment
  ! Variable decleration
  REAL::a,b,c
  REAL::Delta, x1, x2
  ! Main Porgram
  WRITE(*,*) "Please enter the equation coefficients a*x^2+b*x+c"
  WRITE(*,*) "a: ?"
  READ(*,*) a
  WRITE(*,*) "b: ?"
  READ(*,*) b
  WRITE(*,*) "c: ?"
  READ(*,*) c
  Delta=b**2-4*a*c
  IF (Delta >= 0) THEN
    x1=(b+SQRT(Delta))/(2*a)
    x2=(b-SQRT(Delta))/(2*a)
    WRITE(*,*) " The real roots are : ", x1, x2
  ELSE
    WRITE(*,*) " This equation has no real root!"
  ENDIF
  PAUSE
END PROGRAM Equation_solver_fortran