4.已知图象开口向上的二次函数f(x)对任意实数t,f(2+t)=f(2-t)都成立,则f(-1),f(1),f(4),f(5)中最小的是 ( )
A. | f(-1) | B. | f(1) | C. | f(4) | D. | f(5) |
2.设函数f(x)=$\left\{\begin{array}{l}{{x}^{2}-4x+1\\;x≥0}\\{3x+2\\;x<0}\end{array}\right.$若互不相等的实数x1,x2,x3满足f(x1)=f(x2)=f(x3),则x1+x2+x3的取值范围是( )
0 249952 249960 249966 249970 249976 249978 249982 249988 249990 249996 250002 250006 250008 250012 250018 250020 250026 250030 250032 250036 250038 250042 250044 250046 250047 250048 250050 250051 250052 250054 250056 250060 250062 250066 250068 250072 250078 250080 250086 250090 250092 250096 250102 250108 250110 250116 250120 250122 250128 250132 250138 250146 266669
A. | [$\frac{7}{3}$,+∞) | B. | [$\frac{7}{3}$,4) | C. | ($\frac{7}{3}$,$\frac{11}{3}$] | D. | ($\frac{11}{3}$,+∞) |