That equation can represent the relationship among the image distance, 
object distance, and focal length of a lens.  
It could describe the effective resistance of two resistors in parallel, the 
effective inductance of two coils in parallel, or the effective capacitance 
of two capacitors in series.  
Thanks for sharing it.  Now, did you have a question to ask ? 
        
             
        
        
        
Answer:
y = 9 cos [(⅕pi)x]
Step-by-step explanation:
Amplitude = 9
Period = 10
2pi/10 = pi/5
 
        
             
        
        
        
Answer:
alright for the first one you set them equal o each other while for the second you do the same thing
first one:8
second one:5
Step-by-step explanation:
24/3 is x and x=8
for the second one
18+12 is 30 and 30/6 is 5so the second one is 5'
if you want me to clarify more please comment
 
        
                    
             
        
        
        
Answer:
Graphing the derivative with the function can illustrate how to find these turning points. The function is increasing exactly where the derivative is positive, and decreasing exactly where the derivative is negative. On the graph of the derivative find the x-value of the zero to the left of the origin.