semi-latus rectum

(noun)

The latus rectum is a chord perpendicular to the major axis and passing through the focus. The semi-latus rectum is half the latus rectrum. See distance p in.

Related Terms

Examples of semi-latus rectum in the following topics:

  • Kepler's First Law

    • where $(r, \theta)$ are the polar coordinates (from the focus) for the ellipse, $p$ is the semi-latus rectum, and $\epsilon$ is the eccentricity of the ellipse.
    • The semi-major axis $a$ is the arithmetic mean between $r_{\text{min}}$ and $r_{\text{max}}$:
    • The semi-minor axis $b$ is the geometric mean between $r_{\text{min}}$ and $r_{\text{max}}$:
    • The semi-latus rectum $p$ is the harmonic mean between $r_{\text{min}}$ and $r_{\text{max}}$:
    • Also shown are: semi-major axis $a$, semi-minor axis $b$ and semi-latus rectum $p$; center of ellipse and its two foci marked by large dots.