Question

3. Produce the function quadratic(a,b,c) where a, b, and c are the coeffi- cients of the quadratic ax2 + bx +c. The function should return: 1. a list of the two roots of ax2 + bx +c= 0, when two roots exist 2. the first root is the smaller of the two 3. if ax2 + bx +c=0 has no real roots, then return None. 4. if the quadratic has one real root only, then return a list with a single element in it. Some test cases: print (quadratic(1,2,3))# Should be None print(quadratic(1,-2, 1)) # Should be [1.0] print (quadratic(1,0,-2)) # Should be [-1.41421356, 1.41421356] You are allowed to import from math module/library the built in square root function math.sqrt(). [1%]

Answer 1

import math


def quadratic(a, b, c):
    d = (b * b) - (4 * a * c)
    if d < 0 or a == 0:
        return None

    roots = []
    if d == 0:
        roots.append((-b) / (2 * a))
    else:
        r2 = (-b - math.sqrt(d)) / (2 * a)
        r1 = (-b + math.sqrt(d)) / (2 * a)
        roots.append(r1)
        roots.append(r2)
    return roots



# Testing the function here. ignore/remove the code below if not required print (quadratic(1, 2, 3)) print (quadratic(1, -2, 1)) print (quadratic(1, 0, -2))

None [1.0] [1.4142135623730951, -1.4142135623730951] Process finished with exit code o