Cho hàm số . Khẳng định nào sau đây đúng nhất
A. Hàm số liên tục trên 
B. Hàm số không liên tục trên  
C. Hàm số không liên tục trên  
D. Hàm số gián đoạn tại các điểm .

Giá trị của giới hạn $\lim \frac{\sqrt{9{{n}^{2}}-n}-\sqrt{n+2}}{3n-2}$ là 
A. $1.$ 
B. $0.$ 
C. $3.$ 
D. $+\infty .$

A. .
B. .
C. cosx.
D. -cosx.

Cho hàm số y=sinx+cosx, y(3)π4 bằng:
A. 2.
B. -2.
C. 0.
D. Một kết quả khác.

Find a mistake in the four underlined parts of the sentence and correct it:
Were we to run our own business, we would have been more independent.
A. to run
B. own
C. would have been
D. more independent

Find a mistake in the four underlined parts of the sentence and correct it:
If I knew you were coming, I would have met you at the airport.
A. knew
B. were
C. would have
D. at

Find a mistake in the four underlined parts of the sentence and correct it:
In my opinion, he maybe elected because he is honest, knowledgeable and competent.
A. In
B. maybe
C. because
D. knowledgeable

Find a mistake in the four underlined parts of the sentence and correct it:
I’m afraid all our copies have been sold but more have ordered.
A. afraid
B. have been
C. but
D. have ordered

Find a mistake in the four underlined parts of the sentence and correct it:
He is been refused a chance to participate in the Olympic Games.
A. been
B. a
C. to participate
D. the

Find a mistake in the four underlined parts of the sentence and correct it:
It is high time he has told to stop behaving like a child.
A. high
B. has told
C. behaving
D. like