f(x)=x²/(x-1) =1/(1/x-1/x²) =-1/[(1/x-1/2)²-1/4]∵x＞1∴0＜1/x＜1∴0≤(1/x-1/2)²＜1/4∴-1/4≤(1/x-1/2)²-1/4＜0∴x=1/2时,取最小值-1/(-1/4)=4 泪笑为您解答,如若满意,请点...