"""
Slightly extended version of exercise 5.1 
from "Excercises for IN1900". Before we compute
and print the roots, we check that they exist and
use an if-elif-else clause to control the
computation and the output.
"""


import numpy as np

a = float(input("Skriv in a: "))
b = float(input("Skriv in b: "))
c = float(input("Skriv in c: "))


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

if D < 0:
    print("Ingen reelle nullpunkter")
elif D == 0:
    x = - b / (2 * a)
    print(f"Ett nullpunkt, x = {x}")
else:
    x1 = (-b  - np.sqrt(b**2 - 4 * a * c)) / (2 * a)
    x2 = (-b  + np.sqrt(b**2 - 4 * a * c)) / (2 * a)
    print(f"To nullpunkter, x1 = {x1}, x2 = {x2}")

"""
Terminal> python quadratic_input.py 
Skriv in a: 1
Skriv in b: 1
Skriv in c: 1
Ingen reelle nullpunkter
python quadratic_input.py 
Skriv in a: 1
Skriv in b: 2
Skriv in c: 1
Ett nullpunkt, x = -1.0
"""