已知,二次函数f(x)=ax2+bx+c及一次函数g(x)=-bx,其中a、b

题型:解答题

问题:

已知,二次函数f(x)=ax2+bx+c及一次函数g(x)=-bx,其中a、b、c∈R,a>b>c,a+b+c=0.

(Ⅰ)求证:f(x)及g(x)两函数图象相交于相异两点;

(Ⅱ)设f(x)、g(x)两图象交于A、B两点,当AB线段在x轴上射影为A1B1时,试求|A1B1|的取值范围.

考点:二次函数的性质及应用
题型:解答题

某晶体管放大电路的空载放大倍数AK=-80,输入电阻ri=1kΩ和输出电阻r0=3kΩ将信号源(us=10sinωtV,Rs=1kΩ)和负载(RL=5kΩ)接于该放大电路之后(见图),负载电压()。

A.-0.8sinωtV

B.-0.5sinωtV

C.-0.4sinωtV

D.-0.25sinωtV

题型:解答题

短文填空 根据短文内容及首字母提示,补全空格内单词,使短文完整、通顺。(请在答题卡上写出完整单词)

Why do people wear clothes? The answer will probably be “To m 小题1:  me warm and to cover my body ”. That’s why people wear clothes, but people a 小题2:  want to look beautiful.

If people only wear clothes for warmth and to cover their bodies, most clothes will be simple and c 小题3: . But in many countries, clothes sometimes c 小题4:  a lot of money. The clothes are expensive because of fashion.

Successful businessmen, for example, often wear very expensive suits, shirts and ties. So they pay t 小题5:  of dollars for a suit and a tie. It’s still(仍然) just a suit and a tie but they pay these prices because of the f 小题6: designer.

Fashion is always c 小题7: . It means that people who want to be fashionable have to buy new clothes every few months, though(虽然) they only wear last month’s clothes a few t 小题8: . Some people have too m___小题9:___ clothes, but they seldom wear some of these clothes. These clothes are not in fashion any m 小题10: though they are still new.

题型:解答题

如图中三种简单机械使用时,能省力的是        (选填序号),能省距离的是        (选填序号)。

题型:解答题

甲、乙合谋抢劫银行,甲携带猎枪进入银行抢劫货款,乙在外面望风。甲进入银行后,见一顾客正在存钱,就趁其不备,一把抢过即逃出银行,与乙立即逃离。甲、乙的行为构成( )

A.抢夺罪
B.盗窃罪
C.抢劫罪
D.非法持有枪支罪

题型:解答题

起重机在满载时,在指挥和操作上应禁止同时做()种机械动作。

A、两

B、三

C、四

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