An Elementary Treatise on Cubic and Quartic Curves

Front Cover
Deighton, Bell, 1901 - Curves, Cubic - 255 pages
 

Contents

Number of foci when the line at infinity is a multiple tangent
220
333335 Properties of the curve
221
The evolute of an ellipse
223
Its radius of curvature
224
Tangential equation of the evolute of the evolute of an ellipse
225
Connection between the evolute of an ellipse and a fourcusped hypocycloid
226
The involute of a circle
227
Roulette of the centre of a circle whose involute rolls on a straight line is a parabola
228
Roulette of the focus of a parabola which rolls on a straight line is a catenary
229
ᎪᎡᎢ PAGE 347 The tractrix or tractory
230
The equiangular spiral
231
The spiral of Archimedes The hyperbolic spiral The lituus
232
CHAPTER XII
233
A projection introduces five independent constants
234
Projection of a triangle
235
Formulae for projection
236
Any two real points can be projected into the circular points
238
Advantages of projection
239
Some projective properties of nodal cubics
240
Equation of cubic when the circular points are points of inflexion
241
A certain envelope
242
Projection of a quartic having a node and a pair of cusps into a limaçon
243
Projective properties of quartics of the ninth species
244
Projection of a quartic having three biflecnodes into the lemnis cate of Bernoulli
245
The inverse of a focus is a focus of the inverse curve
246
Geometrical interpretation of the general expression for a ternary quartic
247
380381 Discussion of the quartic a³ß+ß³y+y³a0
248
Generalization of the results by projection
251
ADDENDA AND CORRIGENDA I Addition to 2728
253
The six stationary tangents of a trinodal quartic touch a conic
254
Famous problems of antiquity
255

Other editions - View all

Common terms and phrases

Popular passages

Page 162 - Hence, the hyperbola is often defined as the locus of a point which moves so that the product of its distances from two fixed lines is constant.
Page 205 - Cycloid. The cycloid is a curve generated by a point on the circumference of a circle which rolls on a straight line tangent to the circle.
Page 156 - O'; shew that either O or O' is the orthocentre of the triangle ABC. Distinguish between the two cases. 9. Three equal circles pass through the same point A, and their other points of intersection are B, C, D : shew that of the four points A, B, C, D, each is the orthocentre of the triangle formed by joining the other three. 10. From a given point without a circle draw a straight line to the concave circumference so as to be bisected by the convex circumference. When is this problem impossible ?...
Page 24 - J\ but the theorem of Newton's, which has hitherto guided us, is perhaps insufficient immediately to furnish a second relation. Such a relation, however, may be obtained by the following considerations. It is well known that the polar conic of a point of inflexion breaks up into two lines : one of these is the tangent at the point of inflexion, the other will be found to be the locus of the harmonic centres of the n - 1 points in which the curve is cut by a transversal through the point. Exactly...
Page 202 - Hence the polar may be defined as the locus of the points of intersection of tangents at the extremities of chords through a fixed point.
Page 172 - conic' is the locus of a point P which moves so that its distance from a fixed point S, called the 'focus,' is in a constant ratio to its distance from a fixed line called the 'directrix.
Page 231 - Such a curve, in which the tangent at any point makes a constant angle with the radius drawn to that point from a fixed point, is called an equiangular spiral. As the dog at B' is moving at right angles to A'B', the distance A'B
Page 145 - Hence the radical axis of two circles is perpendicular to the line joining their centres. This is geometrically obvious when the circles cut in real points. 84. The three radical axes of three circles taken in pairs meet in a point. If 8= 0, 8' = 0, 8 " = 0 be the equations of three circles (in each of which the coefficient of a?
Page 197 - We have, incidentally, a proof that the pedal of a circle with respect to a point on its circumference...
Page 254 - This is a conic passing through the origin, that is, through the intersection of one of the three pairs of straight lines which can be drawn through the four points.

Bibliographic information