Viewing Saved Work Revert to Last Response Submit Answer 12. [-/3 Points] DETAILS LARAPCALC10 3.3.062.EP. Consider the following function, where R is the revenue (in thousands of dollars) and x is the advertising cost (in thousands of dollars). R = - _X5 + 7x2 + 2, OSX5 5 9 Find R'(x) and R"(x). R'( X) = R" ( X ) = Find the point of diminishing returns for the function, where R is the revenue (in thousands of dollars) and x is the advertising cost (in thous verify your results. (X, R) =