Tìm GTLN, GTNN

a. y= 1+ \(\sqrt{2cos^2x+1}\)

b. y= 1 + 3sin(2x - \(\frac{\pi}{4}\))

c. y= 3 - 2cos²3x

d. y= 1 + \(\sqrt{2+sin2x}\)

e. y= \(\frac{4}{2+sin^{2^{ }}x}\)

\(\sqrt{2x-1}+\sqrt{3x-2}< \sqrt{4x-3}+\sqrt{5x-4}\)

Quả cầu thứ nhất có khối lượng 0.34kg chuyển động với vận tốc 1.2m/s đến va chạm với quả cầu thứ hai chưa biết khối lượng đang đứng yên. Va chạm là đàn hồi xuyên tâm. Sau va chạm, quả cầu thứ nhất vẫn chuyển động theo hướng cũ với vận tốc 0,66m/s. Tính khối lượng và tốc độ quả cầu thứ hai sau va chạm.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.

China - Missing Women

In China the growing difference between the genders is giving signals of alarm to Government authorities. According to the latest census figures, 119 boys are born for every 100 girls. [A] This striking difference is expected to shoot up by the year 2020 with almost 40 million unsettled bachelors. This distribution of the social ecology would create havoc in the future. The social leaders are trying to pressurize the masses into producing more females. The Government has embarked on policies extending innumerable incentives to the families bearing girls.

Monetary support, free education, guaranteed employment is being gifted to parents who gift the country with a girl child. The Government is trying to persuade people to suppress their personal preferences and regulate their community behavior according to the new blueprint to stimulate the girl ratio. [B] Sometimes the Government tries to woo them and sometimes it uses stein policies to force them into it

Consequent to the population explosion, the Government introduced, in the 80's, one child policy in China. Any additional pregnancy had to be terminated. This was aimed to put a check on the teeming millions. [C] The policy had no relation to extermination of girl child in the womb. But the policymakers had no idea about its long term impact. People, with a patriarchic mindset, came up with their preference for a single male child. The idea of a happy family became 'parents with a single male child'.

The Chinese culture has always promoted sons over daughters because the society has been dominated by males. In villages, where hard work is needed to sustain the agriculture, a boy is always preferable due to his superior physical strength compared to that of a girl. [D] In such circumstances, looking forward to a male baby seems justified. If people have to limit their families, it is obvious they would prefer a boy over a girl child. This problem has been accentuated by the use of ultrasound scanning which helps determine the sex of the fetus. This technology has played a crucial role in creating gender imbalance.

The word "teeming" in paragraph 2 is closest in meaning to

A. overflowing

B. female population

C. couples

D. general population

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions. 

Refusal to give a breath sample to the police could lead to your arrest

A. If you refused to be arrested, you have to give a breath sample.

B. You could be arrested for not giving a breath sample to the police.

C. If a breath sample is not given, the police will refuse to arrest you.

D. The police could cause you to give a breath sample to decide whether to arrest you or not

Phát biểu nào sau đây không đúng?

A. Kim loại Fe phản ứng với dung dịch HCl tạo ra muối sắt(II)

B. Dung dịch FeCl 3  phản ứng được với kim loại Fe

C. Kim loại Fe không tan trong dung dịch H 2 SO 4  đặc, nguội

D. Trong các phản ứng hóa học, ion Fe 2 +  chỉ thể hiện tính khử