PROGRAM Quadratic_equation1

! This program the roots of the quadratic equation using the

! quadratic formula

!

! Constant: epsilon

! Variables: a,b,c,discriminant, root1, root2

! discriminant=b**2 - 4.0*a*c

! Input: Coefficients of the quadratic equation a,c and c

! Output: a,b,c, epsilon, discriminant, root 1, root 2

!

IMPLICIT NONE

! Constant declaration

REAL, PARAMETER ::epsilon=1E-6

!Variables declaration

REAL::a.b.c. discriminant, sqrt_discriminant,root1,root 2

!Read in the input

PRINT*, "Enter the three coefficient a,b, and c:"

READ*,a,b,c

! Test if a equals zero. if yes, exit the program

IF (a.LT.epsilon)THEN

PRINT*,"The value of a is zero. Execution terminated"

STOP

END IF

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

PRINT*, "The coefficient are:", a,b,c

PRINT*, "The value of the discriminant is", discriminant

! Check if the discriminant is negative.

! If it is, print message and stop the program

IF (discriminant .LT.0.0)THEN

PRINT*, "Discriminant is negative. The are no REAL roots"

STOP

END IF

!Check if the discriminant is zero

!If it is, calculate and print the single real root

!Otherwise calculate and print the two real roots

IF abs(discriminant)

root1=b**2/2.0*a

PRINT*,"The root is", root 1

ELSE

sqrt_discriminant=SQRT(discriminant)

root1=(-b + sqrt_dsicriminant)/(2.0*a)

root2=(-b - sqrt_discriminant)/(2.0*a)

PRINT*,"The roots are",root1,root2

END IF

END PROGRAM Quadratic_equation1

Question:

2. Modify the Fortran program in Example 4.10 to also calculate the complex roots when the discriminant is negative. The complex roots are given by X= -b-Di 2a where D is the discriminant and 2. Modify the Fortran program in Example 4.10 to also calculate the complex roots when the discriminant is negative. The complex roots are given by X= -b-Di 2a where D is the discriminant and