polar coordinates

from The Collaborative International Dictionary of English v.0.48
Polar \Po"lar\, a. [Cf. F. polaire. See {Pole} of the earth.]
   1. Of or pertaining to one of the poles of the earth, or of a
      sphere; situated near, or proceeding from, one of the
      poles; as, polar regions; polar seas; polar winds.
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   2. Of or pertaining to the magnetic pole, or to the point to
      which the magnetic needle is directed.
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   3. (Geom.) Pertaining to, reckoned from, or having a common
      radiating point; as, polar coordinates.
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   {Polar axis}, that axis of an astronomical instrument, as an
      equatorial, which is parallel to the earths axis.

   {Polar bear} (Zool.), a large bear ({Ursus maritimus} syn.
      {Thalarctos maritimus}) inhabiting the arctic regions. It
      sometimes measures nearly nine feet in length and weighs
      1,600 pounds. It is partially amphibious, very powerful,
      and the most carnivorous of all the bears. The fur is
      white, tinged with yellow. Called also {White bear}. See
      {Bear}.

   {Polar body}, {Polar cell}, or {Polar globule} (Biol.), a
      minute cell which separates by karyokinesis from the ovum
      during its maturation. In the maturation of ordinary ova
      two polar bodies are formed, but in parthogenetic ova only
      one. The first polar body formed is usually larger than
      the second one, and often divides into two after its
      separation from the ovum. Each of the polar bodies removes
      maternal chromatin from the ovum to make room for the
      chromatin of the fertilizing spermatozoon; but their
      functions are not fully understood.

   {Polar circles} (Astron. & Geog.), two circles, each at a
      distance from a pole of the earth equal to the obliquity
      of the ecliptic, or about 23[deg] 28', the northern called
      the arctic circle, and the southern the antarctic circle.
      

   {Polar clock}, a tube, containing a polarizing apparatus,
      turning on an axis parallel to that of the earth, and
      indicating the hour of the day on an hour circle, by being
      turned toward the plane of maximum polarization of the
      light of the sky, which is always 90[deg] from the sun.

   {Polar coordinates}. See under 3d {Coordinate}.

   {Polar dial}, a dial whose plane is parallel to a great
      circle passing through the poles of the earth. --Math.
      Dict.

   {Polar distance}, the angular distance of any point on a
      sphere from one of its poles, particularly of a heavenly
      body from the north pole of the heavens.

   {Polar equation of a line} or {Polar equation of a surface},
      an equation which expresses the relation between the polar
      coordinates of every point of the line or surface.

   {Polar forces} (Physics), forces that are developed and act
      in pairs, with opposite tendencies or properties in the
      two elements, as magnetism, electricity, etc.

   {Polar hare} (Zool.), a large hare of Arctic America ({Lepus
      arcticus}), which turns pure white in winter. It is
      probably a variety of the common European hare ({Lepus
      timidus}).

   {Polar lights}, the aurora borealis or australis.

   {Polar opposition}, or {Polaric opposition} or {Polar
   contrast} or {Polaric contrast} (Logic), an opposition or
      contrast made by the existence of two opposite conceptions
      which are the extremes in a species, as white and black in
      colors; hence, as great an opposition or contrast as
      possible.

   {Polar projection}. See under {Projection}.

   {Polar spherical triangle} (Spherics), a spherical triangle
      whose three angular points are poles of the sides of a
      given triangle. See 4th {Pole}, 2.

   {Polar whale} (Zool.), the right whale, or bowhead. See
      {Whale}.
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from The Collaborative International Dictionary of English v.0.48
Coordinate \Co*["o]r"di*nate\, n.
   1. A thing of the same rank with another thing; one two or
      more persons or things of equal rank, authority, or
      importance.
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            It has neither coordinate nor analogon; it is
            absolutely one.                       --Coleridge.
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   2. pl. (Math.) Lines, or other elements of reference, by
      means of which the position of any point, as of a curve,
      is defined with respect to certain fixed lines, or planes,
      called coordinate axes and coordinate planes. See
      {Abscissa}.

   Note: Coordinates are of several kinds, consisting in some of
         the different cases, of the following elements, namely:
      (a) (Geom. of Two Dimensions) The abscissa and ordinate of
          any point, taken together; as the abscissa PY and
          ordinate PX of the point P (Fig. 2, referred to the
          coordinate axes AY and AX.
      (b) Any radius vector PA (Fig. 1), together with its angle
          of inclination to a fixed line, APX, by which any
          point A in the same plane is referred to that fixed
          line, and a fixed point in it, called the pole, P.
      (c) (Geom. of Three Dimensions) Any three lines, or
          distances, PB, PC, PD (Fig. 3), taken parallel to
          three coordinate axes, AX, AY, AZ, and measured from
          the corresponding coordinate fixed planes, YAZ, XAZ,
          XAY, to any point in space, P, whose position is
          thereby determined with respect to these planes and
          axes.
      (d) A radius vector, the angle which it makes with a fixed
          plane, and the angle which its projection on the plane
          makes with a fixed line line in the plane, by which
          means any point in space at the free extremity of the
          radius vector is referred to that fixed plane and
          fixed line, and a fixed point in that line, the pole
          of the radius vector.
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   {Cartesian coordinates}. See under {Cartesian}.

   {Geographical coordinates}, the latitude and longitude of a
      place, by which its relative situation on the globe is
      known. The height of the above the sea level constitutes a
      third coordinate.

   {Polar coordinates}, coordinates made up of a radius vector
      and its angle of inclination to another line, or a line
      and plane; as those defined in
      (b) and
      (d) above.

   {Rectangular coordinates}, coordinates the axes of which
      intersect at right angles.

   {Rectilinear coordinates}, coordinates made up of right
      lines. Those defined in
      (a) and
      (c) above are called also {Cartesian coordinates}.

   {Trigonometrical coordinates} or {Spherical coordinates},
      elements of reference, by means of which the position of a
      point on the surface of a sphere may be determined with
      respect to two great circles of the sphere.

   {Trilinear coordinates}, coordinates of a point in a plane,
      consisting of the three ratios which the three distances
      of the point from three fixed lines have one to another.
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