- Find the y-intercept - Find the roots (i.e. x - intercepts) - Determine where the function increases and where it increases, along with the maximum and minimum values. - Determine where the function changes concavity along with the inflection points. - Determine the special points, where the value of the function is not defined and try to find the limit when the value of x approachs to this values - Determine the limits of the function when x approachs to positive infinity and negative infinity
- For some of those steps you need to know some concepts of calculus: limits and derivatives along with the rules that let you know if a point is a maximum, a minimum or an inflection point.
With that information you can sketch a polynomial function.