Find the point of diminishing returns (x comma y )for the function R(x), where R(x) represents revenue (in thousands of dollars) and x represents the amount spent on advertising (in thousands of dollars).

Complete Question

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The point of diminishing returns (x , y ) is  (11, 21462)

Step-by-step explanation:

From the question we are told that

     The function is  

Here R(x)  represents revenue (in thousands of dollars) and  x  represents the amount spent on advertising (in thousands of dollars).

           Now  differentiating  R(x) we have  

Finding the second derivative of R(x)

at  inflection point    

    So      

=>          

    substituting value of x into R(x)

Now the point of diminishing returns (x , y ) i.e (x , R(x) ) is

     (11, 21462)

the answer is 8/21

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