#quad1.py                    Version 1
#  This program computes the quadratic formula.  It asks the user
#  to enter the three coefficients of a quadratic equation.
#  The two possible solutions for the variable are determined.
# NB. crashes if radicand is negative, i.e. no solutions case.

import math

  #input the coefficients
a = eval(input("Enter a: "))
b = eval(input("Enter b: "))
c = eval(input("Enter c: "))

  # calculate the two possible values for x.
x1 = (-b + math.sqrt(b**2 - 4*a*c)) / (2 * a)
x2 = (-b - math.sqrt(b**2 - 4*a*c)) / (2 * a)
 
  #display the two solutions
print("x1:", x1, "    x2:", x2)


# Example inputs-output
# 1 1 -2    1 -2
# -1 1 2    -1 2
# 1 -1 -1   phi 1-phi