 | Charles Smith - Geometry, Analytic - 1886 - 268 pages
...of a conic. One definition, due to Mac Cullagh, is as follows : — • A conicoid is the locus of a point which moves so that its distance from a fixed point, called the focus, is in a constant ratio to its distance (measured parallel to a fixed plane) from... | |
 | George Albert Wentworth - Geometry, Analytic - 1886 - 346 pages
...a given triangle. CHAPTER III. THE CIRCLE. EQUATIONS OF THE CIRCLE. 59. The Circle is the locus of a point which moves so that its distance from a fixed point is constant. The fixed point is the centre, and the constant distance the radius, of the circle. NOTE.... | |
 | Arthur Le Sueur - Circle - 1886 - 120 pages
...found by reference to special figures. CHAPTER V. THE PAEABOLA. DEF. — A parabola is the locus of a point which moves so that its distance from a fixed point (the focus) is equal to its distance from a fixed line (the directrix! Equation to a parabola. N- ^.... | |
 | Encyclopedias and dictionaries - 1888 - 900 pages
...point whose distance from a fixed point is constant, or a conic section as the locus of a point whose distance from a fixed point always bears a constant...ratio to its distance from, a fixed straight line. The following is a proposition which is very useful in the discussion of the properties of conic sections.... | |
 | John Daniel Runkle - Geometry, Analytic - 1888 - 370 pages
...CIRCLE. CHAPTER IV. THE OIB0LE. The Equation of the Circle. 68. DEFINITION. — A circle is the locus of a point which moves so that its distance from a fixed point, called the centre, is always equal to a constant length, called the radius. It follows from this definition... | |
 | Sir George Greenhill - Calculus - 1891 - 480 pages
...parabola. But we can easily show that the curve OP satisfies the definition of a parabola as " the locus of a point which moves so that its distance from a fixed point is equal to its distance from a fixed straight line " by making the angle TOS equal to the angle ТОН,... | |
 | George Albert Wentworth - Geometry - 1888 - 466 pages
...pyramid. This theorem is much used' in earth-work. BOOK IX. CONIC SECTIONS. THE PARABOLA. 791. The curve traced by a point which moves so that its distance from a fixed point is always equal to its distance from a fixed line is called a parabola. The curve lies in the plane... | |
 | W. J. Johnston - Geometry, Analytic - 1893 - 448 pages
...describes another right line. CHAPTER VIII THE PARABOLA § 213. A Conic Section or a Conic is the locus of a point which moves so that its distance from a fixed point is to its distance from a fixed line in a constant ratio e : i. Thus if (see fig7 § 214) S is the... | |
 | Robert Lachlan - Geometry - 1893 - 312 pages
...AQ :PN=OA : OP. That is OP:PN=OA:AQ. Thus the reciprocal curve to the given circle is the locus of a point which moves so that its distance from a fixed point varies as its distance from a fixed straight line. 295. If however the circle of reciprocation be concentric... | |
 | Sidney Luxton Loney - Coordinates - 1896 - 447 pages
...„ ^ — - = — 7 • n2 + n'2-l nn CHAPTER VIII. THE CIRCLE. 138. Def. A circle is the locus of a point which moves so that its distance from a fixed point, called the centre, is equal to a given distance. The given distance is called the radius of the circle.... | |
| |
A conic section or conic is the locus of a point which moves so that its distance from a fixed point is in a constant ratio to its distance from a fixed straight line... 
