3.(2022秋•朝阳区校级期中)若函数f(x)=x2+2(a−1)x+2f(x)=x^{2}+2(a-1)x+2f(x)=x2+2(a−1)x+2在区间(−∞(-\infty(−∞,4]4]4]上是减函数,则实数aaa的取值范围是((( )))