# quadrant

The $x$- and $y$-axes the $xy$-plane in four right-angle domains which are called the quadrants^{} of the plane. They are numbered going round the origin in anticlockwise direction so that

$$\{(x,y)\mid x>0,y>0\}$$ |

is the first quadrant,

$$ |

the second quadrant, and so on.

Naturally, one can speak of the quadrants of the complex plane^{}, too.

The lines $y=\pm x$ have as their slope angles $\pm {45}^{\circ}$,
thus halving the quadrant angles; they are called the
quadrant bisectors^{}. Cf. angle bisector as locus.

Title | quadrant |

Canonical name | Quadrant |

Date of creation | 2014-12-16 22:42:51 |

Last modified on | 2014-12-16 22:42:51 |

Owner | Mathprof (13753) |

Last modified by | pahio (2872) |

Numerical id | 14 |

Author | Mathprof (2872) |

Entry type | Definition |

Classification | msc 51N20 |

Synonym | quarter-plane |

Related topic | RightAngle |

Related topic | ConvexAngle |

Related topic | Octant |

Defines | 1st quadrant |

Defines | 2nd quadrant |

Defines | 3rd quadrant |

Defines | 4th quadrant |