x2y2x2y2的知识精选

已知实数x,y满足(x2+y2)(x2+y2-1)=2,则x2+y2=
问题详情:已知实数x,y满足(x2+y2)(x2+y2-1)=2,则x2+y2=________.【回答】.2  解:∵(x2+y2)(x2+y2-1)=2,∴(x2+y2)2-(x2+y2)-2=0,∴(x2+y2-2)(x2+y2+1)=0,∴x2+y2=2或x2+y2=-1,∵x2+y2=-1(舍去),故x2+y2=2,点拨:此题...
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