若log(a)(a^2+1)若log(a)(a^2+1)
若log(a)(a^2+1)若底数a满足01a^2+1>2aa^2-2a+1>0(a-1)^2>0a不等于12a>1a>1/2所以1/2
因为a^2+1>1 且log(a)(a^2+1)<0 所以0 所以log(a)(X)在定义域内单调递减 又因为log(a)(a^2+1)2a >1 所以a<1/2所以 1/2