In below Problems, use the derivative to locate critical points and determine a viewing window that shows

Question:

In below Problems, use the derivative to locate critical points and determine a viewing window that shows all features of the graph. Use a graphing utility to sketch a complete graph.
1. f(x) = x3 - 225x2 + 15,000x - 12,000
2. f(x) = x3 - 15x2 + 16,800x + 80,000
3. f(x) = x4 - 160x3 + 7200x2 - 40,000
4. f(x) = x4 - 240x3 + 16,200x2 - 60,000
5. y = 7.5x4 - x3 + 2