题目内容
【题目】若x≠y,则x4+y4 x3y+xy3(填“>”或“<”)
【答案】>.
【解析】
试题分析:(x4+y4)﹣(x3y+xy3)
=x4+y4﹣x3y﹣xy3)
=x3(x﹣y)﹣y3(x﹣y)
=(x﹣y)(x3﹣y3)
=(x﹣y)2(x2+xy+y2),
∵x≠y,x2+y2≥2xy>0,
∴2xy≥xy,
∴x2+xy+y2>0,
∴x4+y4>x3y+xy3.
故答案为:>.
练习册系列答案
相关题目
题目内容
【题目】若x≠y,则x4+y4 x3y+xy3(填“>”或“<”)
【答案】>.
【解析】
试题分析:(x4+y4)﹣(x3y+xy3)
=x4+y4﹣x3y﹣xy3)
=x3(x﹣y)﹣y3(x﹣y)
=(x﹣y)(x3﹣y3)
=(x﹣y)2(x2+xy+y2),
∵x≠y,x2+y2≥2xy>0,
∴2xy≥xy,
∴x2+xy+y2>0,
∴x4+y4>x3y+xy3.
故答案为:>.