PLEASE HELP ME ON THIS

1. Find the range of values of x for which y = x3 + 5x2 - 8x + 1 is increasing. 2. For what values of x is y = 150): - 2x3 an increasing function? 3. Find the intervals in which f (x) = 2x3 + x2 - 20 x is increasing or decreasing. 4. Find the intervals in which f (x) = x3 - 3 x + 1 is increasing or decreasing. 5. How will you know if a function increases and decreases and how will you locate the maximum and minimum value? Explain