

1. 
Find the value of sin (x + y) if , sin x = , and sin y = . 


A. 

B. 



C. 

D. 



Hint 


2. 
If x and y are acute angles such that sin x = and sin y = , what is the value of cos (x  y)? 


A. 

B. 



C. 

D. 



Hint 


3. 
Use the sum or difference identity for cosine to find the exact value of cos 105° 


A. 

B. 



C. 

D. 



Hint 


4. 
If angles x and y are between 0° and 180° such that cos x =  and cos y = , what is the value of sin (x + y)? 


A. 

B. 



C. 

D. 



Hint 


5. 
Complete the identity tan (  A) = ________. 


A. 
cot A 
B. 
tan A 


C. 
cot A 
D. 
tan A 


Hint 

