4.3 quadratic equation 1

#This program calculates possible solutions for a quadratic equation#
#####################################################################

# Introducing user with a quadratic equation
print("Quadratic equation is any equation with the following form:\n\n\
a * x * x + b * x + c = 0\n\n\
where x is unknown while a, b and c are coefficients known as:\n\
quadratic coefficient, linear coefficient and the constant, respectively.")
print("\n")
print("Note that quadratic coefficient cannot be 0. If a = 0 then the equation is linear, not quadratic.")
print("\n")

import math

def equation_lower(quadratic, linear, constant):
    x = (-b - (math.sqrt(d))) / (2 * a)
    return x

def equation_greater(quadratic, linear, constant):
    y = (-b + (math.sqrt(d))) / (2 * a)
    return y

a = float(input("Enter quadratic coefficient: "))
b = float(input("Enter linear coefficient: "))
c = float(input("Enter constant coefficient: "))

# Discriminant for calculating x
d = b * b - 4 * a * c

x_lower = equation_lower(a,b,c)
x_greater = equation_greater(a,b,c)


# Print the result
print("Possible results are %f and %f" % (x_lower, x_greater))