Newcomb, Simon, 1835-1909 · New York, H. Holt and company · leaf 172
the axis of X is called the sub-normal. To find where the normal cuts the axis of X, we makei/ = 0 in the equation of the normal; then we get (see fig.,§136) CX=x{^-^\ = ex, Hence the subnormal iVi¥= CM- CN = X — .t 1 -J = -r,x \ a J a= (1- e)x\ 156 PLANE ANALYTIC OEOMETRY. 143. Theorem XIII. The… … sin rp _ F_N^sill FNF~ FF sin t/j _ F^Nsin FNF ~ WF {a) Now, FF and F^P are the focal radii whose lengths aregiven by the equations (4) and (5), §120. Also, by §§136and 142, we readily find FN = ae — eV = e{a — ex) = er;FN = ae + e^^• == e{a -\- ex) — er\whence {a) gives e sin FNF = sin i, e sin…
Geometry, Analytic
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
