import math


def quadratic_equation(num1, num2, num3):
    """Solve quadratic equation"""
    delta = (num2 ** 2) - (4 * num1 * num3)
    if delta < 0:
        return None
    elif delta > 0:
        return (-num2 + math.sqrt(delta)) / 2 * num1, (-num2 - math.sqrt(delta)) / 2 * num1
    else:
        return -num2 / 2 * num1, None