函数f（x）=ln（3-4x-4x2），则f（x）的单调递减区间是______．

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问题填空题

函数f（x）=ln（3-4x-4x²），则f（x）的单调递减区间是______．

答案

∵函数f（x）=ln（3-4x-4x²），

∴3-4x-4x²＞0，

解得-

＜x＜

，

∵抛物线t=3-4x-4x²开口向下，对称轴方程为x=-

，

∴由复合函数的单调性的性质，知：

函数f（x）=ln（3-4x-4x²）的单调递减区间是[-

，

）．

故答案为：[-

，

）．

填空题

根据短文内容和首字母提示填空。

The Internet has become part of people's life. A report (1)s that 38% of the students often

use the Internet. Most of them get useful (2)i and use the Internet to help their studies. But many

students don't use it in a good way. Some (3)p games too much, some visit websites they should

not look at. So bad things may happen if students (4)s too much time on the Internet.

It's important for students to use the Internet in a good (5)w . Now we have textbooks which

use many examples to teach students how to (6)u the Internet well. They give useful advice, such

as it's good to (7)r news or find helpful information to study. Some students also (8)m friends

on the Internet. But if you want to have a face-to-face meeting (9)w your online friends, let your

parents know and meet in a (10)s place.

填空题

处理井喷的常用压井方法有（）、（）、（）。