Definition

Noun: - One-half the minor axis of an ellipse: In geometry, the semiminor axis is exactly half the length of the minor axis of an ellipse. The minor axis is the shortest diameter of the ellipse, and the semiminor axis extends from the center of the ellipse to its perimeter along this shortest direction.

Usage

• The semiminor axis is a key parameter for defining the shape and size of an ellipse, often used alongside the semimajor axis.
• It is commonly used in mathematics, astronomy (e.g., describing planetary orbits), and engineering.

Examples

• Noun:
  • To calculate the area of an ellipse, you need to know the length of its semiminor axis and its semimajor axis.
  • The orbit's semiminor axis is significantly shorter than its semimajor axis, indicating a highly elliptical path.

Advanced Usage

• "Length of the semiminor axis": A common phrase specifying the measurement.
  • The length of the semiminor axis for this elliptical track is 50 meters.

Variants and Related Words

• Minor axis (n): The full shortest diameter of an ellipse, of which the semiminor axis is half.
  • The ellipse's minor axis is twice the length of its semiminor axis.
• Semimajor axis (n): One-half the major (longest) axis of an ellipse.
  • The planet's average distance from the star is given by its semimajor axis.

Synonyms

• Half-minor-axis: A descriptive synonym, though "semiminor axis" is the standard technical term.

Related Phrases

• Axis of an ellipse: Refers to either the major or minor line of symmetry through the center.
• Elliptical parameters: The set of measurements, including the semiminor axis, that define an ellipse.

Noun

1. one-half the minor axis of an ellipse