Save Find the intervals on which f(x) is increasing and the intervals on which f(x) is decreasing. Then sketch the graph. Add horizontal tangent lines. f ( x ) = x4 - 50x2 Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The function is increasing on (Type your answer using interval notation. Use a comma to separate answers as needed.) O B. There is no solution