若x2+y2+4x-2y+5=0,求x,(注x2,按ALT+178)
问题描述:
若x2+y2+4x-2y+5=0,求x,(注x2,按ALT+178)
答
(x²+4x+4)+(y²-2y+1)=0
(x+2)²+(y-1)²=0
x+2=0,y-1=0
x=-2,y=1