โž—calculus ii review

Vertical Tangent

Written by the Fiveable Content Team โ€ข Last updated September 2025
Written by the Fiveable Content Team โ€ข Last updated September 2025

Definition

A vertical tangent is a point on a curve where the slope of the tangent line is vertical, meaning it is perpendicular to the x-axis. This occurs when the derivative of the function is undefined at that point, indicating a critical point where the function changes direction.

5 Must Know Facts For Your Next Test

  1. A vertical tangent indicates a critical point where the function is not differentiable, as the derivative is undefined at that point.
  2. Vertical tangents often occur at points where the curve changes direction, such as at a local maximum or minimum.
  3. When working with parametric equations, a vertical tangent can be identified when $\frac{dy}{dt} = 0$ and $\frac{dx}{dt} \neq 0$.
  4. Vertical tangents can be used to analyze the behavior of a curve and identify important features, such as points of inflection or cusps.
  5. The presence of a vertical tangent can also indicate that the function is not continuous at that point, as the left and right limits of the function may not be equal.

Review Questions

  • Explain how a vertical tangent is related to the derivative of a parametric function.
    • A vertical tangent on a parametric curve occurs when the derivative $\frac{dy}{dt}$ is equal to 0, while the derivative $\frac{dx}{dt}$ is not equal to 0. This indicates that the slope of the tangent line is vertical, meaning it is perpendicular to the x-axis. The fact that $\frac{dy}{dt} = 0$ implies that the derivative is undefined at that point, which is a characteristic of a vertical tangent.
  • Describe the significance of a vertical tangent in the context of analyzing the behavior of a parametric curve.
    • Vertical tangents are important features of parametric curves, as they indicate critical points where the function changes direction. These points can represent local maxima, minima, or points of inflection, which are important in understanding the overall shape and behavior of the curve. Additionally, the presence of a vertical tangent suggests that the function may not be continuous at that point, as the left and right limits of the function may not be equal. Analyzing the vertical tangents of a parametric curve can provide valuable insights into its properties and help identify important characteristics.
  • Evaluate how the concept of a vertical tangent relates to the broader understanding of differentiability and continuity in the context of parametric curves.
    • The concept of a vertical tangent is closely tied to the notions of differentiability and continuity in the context of parametric curves. A vertical tangent indicates a point where the derivative of the parametric function is undefined, meaning the function is not differentiable at that point. This lack of differentiability can also imply a lack of continuity, as the left and right limits of the function may not be equal at the point of the vertical tangent. Understanding the relationship between vertical tangents, differentiability, and continuity is crucial in analyzing the properties and behavior of parametric curves, as these concepts are fundamental to the calculus of parametric functions. By identifying vertical tangents and understanding their implications, you can gain a deeper insight into the underlying mathematical structure and characteristics of the parametric curve being studied.