関数——一元二次方程式の解

#-*- coding:utf-8 -*-
import math

def quadratic(a,b,c):
	if not isinstance(a,(int,float)):
		raise TypeError('a is not a number')
	if not isinstance(b,(int,float)):
		raise TypeError('b is not a number')
	if not isinstance(c,(int,float)):
		raise TypeError('c is not a number')
	d=b^2-4*a*c
	if a==0:
		if b==0:
			if c==0:
				return '        '
			else:
				return '    '
		else:
			x1=-c/b
			x2=x1
			return x1,x2
	else:
		if d<0:
			return'    '
		else:
			x1=(-b+math.sqrt(d))/2/a
			x2=(-b-math.sqrt(d))/2/a
			return x1,x2