Answer Happy

Suppose the derivative of fis f'(x)=x+15. a. What are the critical points of 1? b. On what open intervals is fincreasing or decreasing? a.x= (Simplify your answer. Use a comma to separate answers as needed.) b. Select the correct choice below and, if necessary, fill in the answer box(es) to complete your choice. OA. The function is increasing on the open intervals and decreasing on the open interval(s) (Simplify your answers. Type your answers in interval notation. Use a comma to separate answers as needed.) The function is never decreasing. OB. The function is increasing on the open interval(s) (Simplify your answer. Type your answer in interval notation. Use a comma to separate answers as needed.) The function is never increasing. OC. The function is decreasing on the open interval(s) (Simplify your answer. Type your answer in interval notation. Use a comma to separate answers as needed.) OD. The function is never increasing or decreasing.