搜题请搜索小程序“爱下问搜题”
问题 填空题
（理科）已知函数f(x)=
(3-a)x-3，(x≤7)
ax-6，(x＞7)
若x∈Z时，函数f（x）为递增函数，则实数a的取值范围为______．
答案

∵函数f(x)=

(3-a)x-3，(x≤7)
ax-6，(x＞7)
若x∈Z时，函数f（x）为递增函数，

∴

3-a＞0
a＞1
f(7)＜f(8)
即
a＜3
a＞1
a＜-9或a＞2

解得2＜a＜3

故答案为：（2，3）

选择题

Let's find the card ____ Santa.      [ ]

A. by            

B. of          

C. with
查看答案
填空题

根据首字母及句意补全单词

1. She d_____ to take a long vacation.

2.I have to b_____ my little sister this afternoon.

3. Amy is an active girl .She is o_____.

4. They are twin sisters. They also have some differences, t_____.

5. Some students exercise once or t_____ a week.
查看答案