projective line
短语词形变化
projective lines
复数
projective lines
释义与例句
n.
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1.
A line that includes a point at infinity; a line in a projective space; a projective space of dimension 1.
A projective line in P²( R ), consists of the projective points defined by coplanar directions in R ³. In other words, just as the points in P²( R ) correspond to one-dimensional subspaces in R ³, the projective lines correspond to two-dimensional subspaces in R ³.
2008, Catriona Maclean (translator), Daniel Perrin, Algebraic Geometry: An Introduction, [1995, D. Perrin, Géométrie algébrique] Springer, page 37, Consider the projective line mathbf P¹, with homogeneous coordinates x and t and open sets U_0(x ne 0) and U_1(t ne 0).