MBA英语词汇基础练习题及答案

2019年MBA数学：基础练习题及答案(二)

1、已知f(xy)=f(x) f(y)且f′(1)=a,x≠0，求f′(x)=? (答案为a/x)

【思路1】原方程两边对Y实行求偏导

xf′(xy)=f′(y) 其中f′(xy)与f′(y)都是对y偏导数

xf′(x*1)=f′(1)=a 得 f′(x)=a/x

【思路2】当⊿x→0时，令x ⊿x=xz则z=(1 ⊿x/x)

由f′(x)=[f(x ⊿x )-f(x)]/ ⊿x

={f[x(1 ⊿x/x)]-f(x)}/⊿x

=[f(x) f(1 ⊿x/x)-f(x)]/⊿x

=f(1 ⊿x/x)/⊿x =f′(1)/x=a/x

2、已知函数f(x y,x-y)=x2-y2, 则f对x的偏导数加f对y的偏导数等于? (a)2x-2y (b)x y

【思路1】设U=x y,v=x-y

f(u,v)=uv

f′x=f′u*u′x f′v*v′x=v*1 u*1=u v

f′y=f′u*u′y f′v*v′y=v-u

f′x f′y=u v v-u=2v=2(x-y)=2x-2y 选A

【思路2】由已知f(x y,x-y)=(x y)(x-y),

令u=x y, v=x-y, 则f(u,v)=uv,于是f(x,y)=xy,故答案为(b). 结论：b应该是对的，复合函数是相对与自变量来说的，自变量与字母形式无关。

3、已知方程7x2-(k 13)x k2-k-2=0的两个实根分别在区间(0，1)和(1，2)内，则k的取值范围是什么?答案为(-2，-1)U(3，4)

【思路】画图可得f(0)>0,f(1)0代入计算即可。

4、A,B是一次随机实验的两个事件，则___

A. A-(B-A)=A-B B. A-(B-A)=A

【思路】B,利用定义可得。

(B卷)

Vocabulary(15 points)

Direction: There are 30 incomplete sentences in this part .For each

sentence there are four choices marked A) B) C) D) .Choose the one best

completes the sentence.

1. The opening speeches sounded more like ________ of war than

offering of peace.

A) announce B) demand C) declaration D) demonstration

2. Their marriage was already ________ even before his wife went

abroad.

A) fade away B) fall apart C) get away D) go down

3. I’m pleased to hear of your job offer-----all that hard work at school

has obviously ____.

A) paid off B)taken its off C) made a difference D) shown up

4. A rich old lady _______ dead at home for two weeks---and nobody

knew anything about it.

A. lived B. stayed C. lay D. kept

5. Smart cars ________which can monitor one’s driving and the driving

第1页 2015成人学位英语考试词汇练习题及答案

1. Mary, I_____John of his promise to help you.【B】

A. told B. reminded C. warned D. advised

2. I a bank account after I made﹩1 000 by doing a part-time job during the summer vacation.【B】

A.borrowed B.opened C.entered D.ordered

3. Clinical evidence began to__________, suggesting that the new drugs had a wider range of useful

activities than had been predicted from experiments in animals.【D】

A. operate B. strengthten

C. approve D. accumulate

4. The minister said. “We are ready for discussions with any legal parties, but we’ll never_______

with criminals.”【A】

A. negotiate B. quarrel C. argue D. consult

5. Know font if we want to the success but they may also________ out thinking.【B】

A. direct B. limit C. change D. improve

6. You are old enough to your own living.【D】

考研英语词汇练习题及答案（一）

1. This rock has to be _______ in order to build a road.

A. blasted B.explored C.hired D.maintained

2. He did not go to the party last night, which _______ her feelings deeply.

A. wounded B.injured C.hurt D.injury

3.When they returned to the river, they found that the boat had _______ away.

A.framed B.frosted C.frowned D.floated

4.If you need further information, please _______ our office.

A.constant B.construct C.contact D.contain

5.During the war, many soldiers were killed not by _______, but by disease.

A.bulledts B.devil C.bible D.depth

6.We watched the ship until it became only a _______ in the distance.

A. point B.jar C.stove D.dot

7.The English proverb ‘_______ the rod and spoil the child’ means that if you deep from

punishing the child, you will spoil its character.