若实数x、y满足(x2+y2+2)(x2+y2-1)=0,则x2+y2=_.
问题描述:
若实数x、y满足(x2+y2+2)(x2+y2-1)=0,则x2+y2=______.
答
设x2+y2=m,方程化为(m+2)(m-1)=0
∴m1=-2,m2=1
∵x2+y2≥0
∴m1=-2舍去,即x2+y2=1.
故本题答案为:1