Tìm tập xác định

a, \(y=sin\dfrac{\pi}{2x-1}\)

b, \(y=sin\left(\dfrac{x}{\sqrt{x^2-4}}\right)\)

c, \(y=3cot\left(2x+3\right)\)

d, \(y=2sin3x+tan\left(1-4x\right)\)

e, \(y=\dfrac{sinx}{sin^2x-cos^2x}\)

giúp tớ chứ vừa lên 11 mà lú quá huhu

Một màng xà phòng được tại ra bởi một khung dây theo hình chữ nhật đặt nằm ngang có cạnh AB = 5cm di động được. Biết người ta cần thực hiện một công A =3,2.10^-4J để làm tăng diện tích màng xà phòng bằng cách dịch chuyển đều cạnh AB một đoạn 8cm. Xác định hệ số căng bề mặt của nước xà phòng ?

1. Trong mặt phẳng Oxy, cho đường tròn (C): \(x^2+y^2-2x+4y-4=0\)và điểm M(-1;-3). Gọi I là tâm của (C). Viết phương trình đường thẳng đi qua M và cắt (C) tại hai điểm A,B sao cho tam giác IAB có diện tích lớn nhất

2. Trong mặt phẳng Oxy, cho đường tròn (C): \(x^2+y^2+4x+4y-17=0\) và điểm A(6;17). Viết phương trình tiếp tuyến của (C) biế tiếp tuyến đi qua điểm A.

1. tìm min của hàm số \(P=\dfrac{1}{x}+\dfrac{2}{1-x}\)với 0 < x < 1

2. tìm max của biểu thức \(P=\dfrac{xy\sqrt{z-1}+yz\sqrt{x-2}+zx\sqrt{y-3}}{xyz}\)với x >=2; y>=3; z >=1

100. I’ll go to the football match tomorrow if the weather’s fine.

Unless..........................................................................................................

101. It would be a good idea to see the Director first.

You’d...........................................................................................................

102. It is unnecessary to bring anything else.

Nothing........................................................................................................

103. He managed to mend the car.

He succeeded................................................................................................

104. I’m quite certain that wasn’t John’s wife, she’s Polish.

That couldn’t................................................................................................

105. You should have your eyes tested as soon as possiblt.

I advise.........................................................................................................

106.We can’t afford to buy that car.

That car........................................................................................................

107. I’d prefer you not to tell John about my new job.

I’d rather.......................................................................................................

108. Is this the way to the College?

Am I going...................................................................................................

109. Learning Polish is more difficult thanlearning English.

It isn’t...........................................................................................................

110. I suggest we go to the cinema tonight.

Why............................................................................................................ ?

90. I was annoyed because he switched off the TV without asking.

I objected......................................................................................................

91. The manager said the work must be finished by 5 p.m.

The manager insisted on the.........................................................................

92. Nowadays people don’t learn foreign languages the same way as I did.

Nowadays people learn.................................................................................

93. It would be pity to give up.

Let’s.............................................................................................................

94. Although he didn’t have any experience, he got the job.

In spite..........................................................................................................

95. Stopping smoking improved my health.

My health.....................................................................................................

96. It’s been such a long time since I last saw you.

It’s been so...................................................................................................

97. It’s impossible for him to pass the examination.

There is no possibility of..............................................................................

98. All the shops are closed on Saturday.

None.............................................................................................................

99. It is more difficult to teach young children than adults.

Young children.............................................................................................

100. I’ll go to the football match tomorrow if the weather’s fine.

Unless..........................................................................................................

101. It would be a good idea to see the Director first.

You’d...........................................................................................................

102. It is unnecessary to bring anything else.

Nothing........................................................................................................

103. He managed to mend the car.

He succeeded................................................................................................

104. I’m quite certain that wasn’t John’s wife, she’s Polish.

That couldn’t................................................................................................

105. You should have your eyes tested as soon as possiblt.

I advise.........................................................................................................

106.We can’t afford to buy that car.

That car........................................................................................................

107. I’d prefer you not to tell John about my new job.

I’d rather.......................................................................................................

108. Is this the way to the College?

Am I going...................................................................................................

109. Learning Polish is more difficult thanlearning English.

It isn’t...........................................................................................................

110. I suggest we go to the cinema tonight.

Why............................................................................................................ ?

111. Would you like to come to the concert with me?

Are you........................................................................................................

112. People say that he was an excellent actor.

He is.............................................................................................................

113. This is the last time I speak to you.

Never............................................................................................................

114. I have never visited this museum before.

This is...........................................................................................................

115. I don’t think it’s possible you saw Mary in the street yesterday because she went to work abroad last month.

You..............................................................................................................

116. I didn’t think there would be such a lot os furniture in the house.

There............................................................................................................

117. It was only May but the sea was so warm we went swimming.

The sea was warm........................................................................................

118. Travelling by car is usually more comfortable than travelling by train.

It is not usually.............................................................................................

119. “Why don’t you buy a new TV set?” John suggested.

John suggested.............................................................................................

120. They will get there too late to be able to send some information.

By the time...................................................................................................

121. Jane will only come to the party if Peter is invited.

Unless Peter..................................................................................................

122. “I am sorry I lost your book, Mary”, said John.

John apologised............................................................................................

123. Would you like to go for a walk in the park?

Do you feel...................................................................................................

124.I’m not tall enough to reach the shelf.

The shelf.......................................................................................................

125. My son will be nineteen on  July 10.

July 10 is......................................................................................................

126. I’m going to learn French next year.

French is.......................................................................................................

127. It annoys me when students ask silly questions.

I can’t stand..................................................................................................

128. Not only does she speak English but she also speaks French.

As well.........................................................................................................

129. He does almost no work.

He hardly......................................................................................................

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