Sorry gurl but I don’t even understand my own algebra
        
                    
             
        
        
        
Answer: sin = ±
 = ±  
 
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A 
⟹ sinA = ±
As required,  set A =  &   cos a=
   &   cos a=   ,thus we get
    ,thus we get
sin  =±
 =±  
   
∴ sin =±
 =± = ±
 = ±  
 
    since ,360° <  <450°
 <450°
              ,180° <  <225°
 <225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative. 
hope it helped!
     
 
        
             
        
        
        
Answer:
I believe the answer is B sorry if I'm wrong
 
        
             
        
        
        
Answer:
$171.12
Step-by-step explanation:
Including the tip and cost, it is 171.12. Multiply 148.6 by 1.15, which includes the total cost plus another 15% for the tip.
 
        
             
        
        
        
Answer:
(S - 3) + (X - 3) = B
Step-by-step explanation:
S = amount of shirts
X = amount of jeans
B = total amount she would pay
(S - 3) + (X - 3) = B