Find the point of diminishing returns left parenthesis x comma y right parenthesis(x,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).

Find the point of diminishing returns left parenthesis x comma y right parenthesisxy for the function Rx where Rx represents revenue in thousands of dollars and class=