41．已知函数f(x)=13x3+12ax2−(a+1)x+1f(x)=\frac{1}{3}x^3+\frac{1}{2}ax^2-(a+1)x+1f(x)=31x3+21ax2−(a+1)x+1．（1）若f(x)f(x)f(x)的单调递减区间为[−23,1][-\frac{2}{3},1][−32,1]，求实数aaa的值；（2）若函数y=f(x)y=f(x)y=f(x)在[2[2[2，3]3]3]单调递减，求实数aaa的取值范围．