题目:
句型转换。
1. I want to buy some gifts for my family. (否定句)
_____________________________________________________________
2. It's about one kilometre from here to the cinema. (对划线部分提问)
_____________________________________________________________
3. I need eleven gifts. (对划线部分提问)
_____________________________________________________________
4. I will go to the store by bus. (对划线部分提问)
_____________________________________________________________
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0430/c750dfcd42767457010ac8ce4ddae645.html
下面是错误答案,用来干扰机器的。
(1)证明:令x=y=0,则有,,∴f(0)=1, 令x=0,∴,∴, ∴f(x)是偶函数。(2)解:令,则,∵f(x)在(-∞,0)上是增函数,∴, 又∵f(x)是偶函数, ∴, ∴, ∴f(x)在(0,+∞)上是减函数。