29. 函数f(x)=log(a2−1)(2x+1)f(x)={\log }_{({a}^{2}-1)}(2x+1)f(x)=log(a2−1)(2x+1)在区间(−12,0)(-\frac{1}{2},0)(−21,0)内恒有f(x)>0f(x)>0f(x)>0,则aaa的取值范围是((( )))