To formally determine the concavity of a graph, one must use that graph's second [[derivative]]. If the second derivative at a point on the graph is negative, then the graph at that point is concave down, and vice-versa should it be positive. If the second derivative at a point equals [[zero]], then there is no concavity; should the concavity be different on either side of that point, then this point is said to be an '''inflection point'''. | To formally determine the concavity of a graph, one must use that graph's second [[derivative]]. If the second derivative at a point on the graph is negative, then the graph at that point is concave down, and vice-versa should it be positive. If the second derivative at a point equals [[zero]], then there is no concavity; should the concavity be different on either side of that point, then this point is said to be an '''inflection point'''. |