偶函数f（x）在（-∞，+∞）内可导，且f'（1）=-2，f（x+2）=f（x-_爱下问搜题

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问题选择题

偶函数f（x）在（-∞，+∞）内可导，且f'（1）=-2，f（x+2）=f（x-2），则曲线y=f（x）在点（-5，f（-5））处切线的斜率为（　　）

A．2

B．-2

C．1

D．-1

答案

由f（x）在（-∞，+∞）内可导，对f（x+2）=f（x-2）两边求导得：

f′（x+2）（x+2）′=f′（x-2）（x-2）′，即f′（x+2）=f′（x-2）①，

由f（x）为偶函数，得到f（-x）=f（x），

故f′（-x）（-x）′=f′（x），即f′（-x）=-f′（x）②，

则f′（x+2+2）=f′（x+2-2），即f′（x+4）=f′（x），

所以f′（-5）=f′（-1）=-f′（1）=2，即所求切线的斜率为2．

故选A

单项选择题

村民委员会和居民委员会的法律性质是( )。

A．基层 * * 组织

B．基层群众性自治组织

C．基层人民团体

D．地方自治组织

单项选择题

Airplane manufacturer: I object to your characterization of our X-387 jets as dangerous. No X-387 in commercial use has ever crashed or even had a serious malfunction.
Airline regulator: The problem with the X-387 is not that it, itself, malfunctions, but that it creates a turbulence in its wake that can create hazardous conditions for aircraft in its vicinity.
The airline regulator responds to the manufacturer by doing which of the following

A．Characterizing the manufacturer’s assertion as stemming from subjective interest rather than from objective evaluation of the facts.

B．Drawing attention to the fact that the manufacturer’s interpretation of the word "dangerous" is too narrow.

C．Invoking evidence that the manufacturer has explicitly dismissed as irrelevant to the point at issue.

D．Citing statistical evidence that refutes the manufacturer’s claim.

E．(E) Casting doubt on the extent of the manufacturer’s knowledge of the number of recent airline disasters.