3.(2023春•河池月考)已知函数f(x)=ax2+ln(x+1)+xf(x)=ax^{2}+ln(x+1)+xf(x)=ax2+ln(x+1)+x,对任意的x1x_{1}x1,x2∈(1,+∞)x_{2}\in (1,+\infty )x2∈(1,+∞),f′(x)<1f'(x)<1f′(x)<1恒成立,则实数aaa的取值范围是((( )))