Turning Points

Definition

Turning points are the critical points on the graph of a polynomial function where the direction of the curve changes. They represent the local maxima and minima of the function and are essential in understanding the behavior and shape of the polynomial graph.

5 Must Know Facts For Your Next Test

1. Turning points are the points on the graph of a polynomial function where the function changes from increasing to decreasing, or vice versa.
2. The number of turning points on the graph of a polynomial function of degree $n$ is at most $n-1$.
3. Turning points can be used to determine the local maxima and minima of a polynomial function, which are important in understanding the function's behavior.
4. The first derivative of a polynomial function is zero at its turning points, and the second derivative changes sign at the turning points.
5. Identifying the turning points of a polynomial function is crucial in sketching its graph and understanding its properties, such as its end behavior and points of interest.

Review Questions

• Explain how turning points are related to the local maxima and minima of a polynomial function.
  • Turning points on the graph of a polynomial function represent the local maxima and minima of the function. At a local maximum, the function value is greater than the values immediately before and after it, while at a local minimum, the function value is less than the values immediately before and after it. The turning points indicate the points where the function changes from increasing to decreasing, or vice versa, and are essential in understanding the overall shape and behavior of the polynomial graph.
• Describe the relationship between the first and second derivatives of a polynomial function and its turning points.
  • The turning points of a polynomial function are closely related to its first and second derivatives. At a turning point, the first derivative of the function is equal to zero, as the function changes from increasing to decreasing, or vice versa. Additionally, the second derivative of the function changes sign at the turning points, indicating a change in the concavity of the graph. This relationship between the derivatives and the turning points is a crucial tool in analyzing the properties and behavior of polynomial functions.
• Evaluate the importance of identifying the turning points of a polynomial function in the context of sketching its graph and understanding its properties.
  • Identifying the turning points of a polynomial function is essential for sketching its graph and understanding its overall properties. The turning points provide information about the local maxima and minima of the function, which are important in determining the shape and behavior of the graph. By locating the turning points, you can better understand the end behavior of the function, as well as any points of interest, such as local extrema. This knowledge is crucial in sketching an accurate graph of the polynomial function and analyzing its characteristics, such as its domain, range, and any asymptotic behavior.

Related terms

Local Maxima: The highest point on a portion of a graph, where the function value is greater than the values immediately before and after it.

Local Minima: The lowest point on a portion of a graph, where the function value is less than the values immediately before and after it.

Inflection Point: A point on the graph of a function where the concavity of the curve changes from upward to downward, or vice versa.