#quadLoop.py
#solve as many quadratic equations as user wants.
#Ensure coefficient a is not zero.

import math

again = 'y'
while again == 'y':
    
    print("Solve a quadratic equation.  Enter the coefficients of a quadratic equation ")

    a = eval(input("Enter a: "))
    while a == 0:  #ensure that a is not zero
        a = eval(input("a can not be 0. Enter a again: "))
                 
    b = eval(input("Enter b: "))
    c = eval(input("Enter c: "))

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

    if discriminant > 0:
        # calculate the two possible real values for x.
        x1 = (-b + math.sqrt(discriminant)) / (2 * a)
        x2 = (-b - math.sqrt(discriminant)) / (2 * a)

        print("Two roots (solutions)  x1:", x1, "   x2: ", x2)
    elif discriminant == 0:
        #one real root
        x1 = -b / (2*a)
        print("One root (solution)  x=", x1)
    else:
        #no real roots
        print("No roots. Discriminant is negative.")

    again = input("Again? (y or n): ")

"""
1 1 -2    1 -2
-1 1 2    -1 2
2 2 -2    0.618034  -1.61803
1 1 1     no roots
1 2 1     one root -1
"""