A. -sinx.
B. sinx.
C. .
D. .

A. f'(0) = 0
B. Không có.
C. f'(0-) = 0; f'(0+) không có.
D. f'(0+) = 0; f'(0-) không có.

Choose the best answer for the following sentence:
She suffered a lot from ____________  after the death of her husband.
 
A. depress                 
B. depressingly       
C. depressed           
D. depression

Choose the best answer for the following sentence:
He is not in town; he ____________ on a special mission.  
A. is sending          
B. will be sent             
C. has sent               
D. has been sent

Choose the best answer for the following sentence:
The university ____________ by private funds as well as by tuition income and grants. 
A. is supported             
B. supports                  
C. is supporting                   
D. has supported

Choose the best answer for the following sentence:
Having finished ______________________ the reading report, I began to listen to music. 
A. to write               
B. to have written                  
C. writing                     
D. written

Choose the best answer for the following sentence:
 The burglar _____________________.
 
A. has been disappeared with the cash                                    
B. disappeared the cash
C. disappeared with the cash                            
D. was disappeared with the cash

Choose the best answer for the following sentence:
This is about the _____________ that people with epilepsy and their families successfully manage each and every day. 
A. challenges                      
B. objections                   
C. supports                       
D. threats

Đạo hàm của hàm số f(x) = (x2 + 1)4 tại điểm x = -1 là:
A. -32.
B. 30.
C. -64.
D. 12.

Cho f(x) = cosx.cos3x. Đạo hàm của hàm f(x) tại điếm x =  bằng:
A. 2.
B. .
C. 1.
D. -1.