A general geometry and calculus : including book I. of the general geometry, treating of loci in a plane; and an elementary course in the differential and integral calculus (1881)
Olney, Edward, 1827-1887 · New York : Sheldon and Co. · leaf 226
these curvesare symmetrical with re-spect to any diameter. 327* ScH.—These principles, togetherwith others already known, enable us tofind the centre, axes, and foci of the curves,geometrically, when the perimeters aloneare given. Thus, in the case of the ellipse,let the curve NHIM be given, to… … Fig. 216.
Geometry, Analytic · Calculus
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