Derivative tests can be used to approximate the graph of by determining (local/absolute) extrema and concavity.
- Identify asymptotes before differentiation (e.g. variable in the denominator)
- Note: If is defined over a closed interval , then has an absolute maximum or minimum in . All absolute max/min occurs at or at the end points ()
- Note: if there is a variable in the denominator, find the critical point (solve for denominator )