Answer:
None of the above
Step-by-step explanation:
-9 tells the distance between her hand and the keys
 
        
             
        
        
        
Answer:
The Law of Cosine :  cos C = 
Step-by-step explanation:
See the figure to understand the proof :
Let A Triangle ABC with sides a,b,c,
Draw a perpendicular on base AC of height H meet at point D
Divide base length b as AD = x -b   and    CD = x 
By Pythagoras Theorem 
In Triangle BDC             And     In Triangle BDA
a² = h² + x²     (  1  )                        c² = h² + (x-b)²
                                                       c² = h² + x² + b² - 2xb   ...(. 2)
From above eq 1 and 2
c² = (a² - x²) + x² + b² - 2xb
or, c² = a² + b² - 2xb                    .....(3)
Again in ΔBDC
cos C = 
Or, cos C = 
∴ x= a cos C
Now put ht value of x in eq 3
I.e, c² = a² + b² - 2ab cos C
Hence , cos C =  Proved   Answer
      Proved   Answer 
 
        
             
        
        
        
Do you need the fraction? I don’t understand what you are asking
        
             
        
        
        
Answer:
2/3 magazines per hour
Step-by-step explanation:
Olivia writes 2 new sheets of magazines in 3 hours.
The rate per hour at with she writes the sheets of magazines is the number of sheets divided by the amount of time taken to write the sheets.
Hence, the rate per hour is:
R = 2 / 3 = 2/3 magazines per hour
The rate per hour at with she writes the sheets of magazines is 2/3 magazines per hour.