NUMBER 34 ONLY

Business In Exercises 33 and 34, find the point of diminishing returns for the given functions, where R(x) represents revenue, in thousands of dollars, and x represents the amount spent on adver- tising, in thousands of dollars. (See Example 5,) 33. R(x) = 10,000 - x3 + 42x2 + 800x; 0 = x = 20 4 34. R(x) = x' + 66x- + 1050x - 400); 0 = x = 25 27