Type the following program exactly as shown:
! This program find the roots of equations of the 2nd degree
! with coefficients a, b and c
program Equation
implicit none
real*4 a, b, c, delta
real*4 root1, root2
integer*1 count
! ----------------------------------------------Prompt and Input
print*, "Solves ax^2 + bx + c = 0"
print*, "Enter the coefficients a,b,c separated by commas..."
read*, a, b, c
! ----------------------------------------------Validate
! ----------------------------------------------Find delta
delta = b**2 - 4.* a * c
! ----------------------------------------------Determine Roots
if (delta .GT. 0.) then
root1 = (-b + sqrt(delta)) / (2. * a)
root2 = (-b - sqrt(delta)) / (2. * a)
count = 2
else if (delta .LT. 0.) then
count = 0
else
root1 = -b / (2. * a)
count = 1
end if
! ----------------------------------------------Show Results
if (count .EQ. 2) then
write(*,20) " Equation has two roots: ", root1, ", ", root2
else if (count .EQ. 1) then
write(*,20) " Equation has one root: ", root1
else
write(*,20) " Equation has no real roots!"
end if
20 format(1x, A, F10.4, A, F10.4)
! ----------------------------------------------Verify root1
if (count .GT. 0) then
print*, "Verifying the first root by computing the L.H.S.:"
end if
! ----------------------------------------------
end