def quadratic(a, b, c):
 b24ac = math.sqrt(((b * b) - ((4.0 * a) * c)))
 return list(set([((((- b) - b24ac) / 2.0) * a), ((((- b) + b24ac) / 2.0) * a)]))

def quadratic ( a , b , c ) : b24ac = math . sqrt ( ( ( b * b ) - ( ( 4.0 * a ) * c ) ) ) return list ( set ( [ ( ( ( ( - b ) - b24ac ) / 2.0 ) * a ) , ( ( ( ( - b ) + b24ac ) / 2.0 ) * a ) ] ) )
quadratic problem: f(x) = ||wx - y|| .