Tx²+Ty²+4T=x+yTx²-x+(Ty²-y+4T)=0x是实数则△>=01-4T²y²+4Ty+16T²>=04T²y²-4Ty-(16T²+1)<=0x>0,y>凳薯差0则显然T>0所以4T²>0则二次函数开口向上而4T²y²-4Ty-(16T²+1)<=0有解即函数能娶到小于等于0的值所以枣皮和横轴有交点即△>=0所以16T²-256T^4+16T²>=0两边除以-32T²8T²-1<=0-√2/手禅4<=T<=√2/4 所以最大值是√2/4