Relative Min and Max
Type in your function inside the green box. Choose a Left X and a Right X that are outside of the relative extremum. Sometimes you may have to choose a very small Left X and a very Large X if you are unsure of where the relative extremum may be. You may check "Point" to view another point on the graph, and use the red slider to move that point. Check "Tangent" to view the tangent line, and check "Trace" to see where the graph is decreasing (Red Highlights) and increasing (Green Highlights). The highlights will come together at relative extremum. The "Auto Focus" feature is in beta, but may help you if you don't feel like dragging your mouse around :p