x1>1,x2>1所以x1-1>0,x2-1>0两个数都大于0则相加,相乘都大于0所以(x1-1)+(x2-1)=x1+x2-2>0(x1-1)(x2-1)=x1x2-(x1+x2)+1>0x1+x2=1-2k,x1x2=k²所以1-2k-2>0,k0,k²+2k>0,k0所以k=0-4k+1>=0k...