x2;+y2+6x-4y+13=0 求(x+y)2008
问题描述:
x2;+y2+6x-4y+13=0 求(x+y)2008
答
x2+y2+6x-4y+13
=(x+3)^2+(y-2)^2
=0
x+3=0,y-2=0
x=-3,y=2
(x+y)^2008=(-3+2)^2008=1