# Oblate spheroid equation(c<a)

## Description

A spheroid, or ellipsoid of revolution is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters.An oblate spheroid is a rotationally symmetric ellipsoid having a polar axis shorter than the diameter of the equatorial circle whose plane bisects it (like a lentil).

## Variables

x | X-coordinate of the point (dimensionless) |

a | Semi-major axis ( the equatorial radius of the spheroid) (dimensionless) |

y | Y-Coordinate of the point (ordinate) (dimensionless) |

b | Semi-minor axis (dimensionless) |

z | Z-coordinate of the point (dimensionless) |

c | Distance from centre to pole along the symmetry axis (c<a) (dimensionless) |