https://math.stackexchange.com › questions › 788870 › is-a-ray-actually-a-half-line
Is a ray actually a half-line? - Mathematics Stack ExchangeA half-line is just a set of the form $a + tb$ for $t \ge 0$, in a vector space over the reals. In the plane this just amounts to lines that are "cut off", i.e. have an endpoint, but then extend towards infinity. Say $\{(x,0): x \ge 0\}$, the positive x-axis, or the negative one too, is an example. (in the former case we have $a = (0,0), b = (1 ...
https://mathvox.com › ... › chapter-1-basic-figures-of-plane-geometry › a-ray
A ray (or half-line) - MATHVOXRays (or half-lines) the same as lines are designated by lowercase Latin letters: ray a or ray b. A half-line (or ray) is also designated by two points: the initial point and another point belonging to the half-line.
https://en.wikipedia.org › wiki › Half-space_(geometry)
Half-space (geometry) - WikipediaIn geometry, a half-space is either of the two parts into which a plane divides the three-dimensional Euclidean space. If the space is two-dimensional, then a half-space is called a half-plane (open or closed). A half-space in a one-dimensional space is called a half-line or ray.
https://math.libretexts.org › Bookshelves › Applied_Mathematics › Contemporary_Mathematics...
10.2: Points, Lines, and Planes - Mathematics LibreTextsA ray is defined by two points on the line; the first point is where the ray begins, and the second point gives the line direction. A half-line is defined by two points, one where the line starts and the other to give direction, but an open circle at the starting point indicates that the starting point is not part of the half-line. A ...
https://math.info › Geometry › Lines_Rays_Segments
Lines, Rays and Line Segments - Math . infoA ray is occasionally referred to as a half line. Rays begin at one point and continue indefinitely in a single direction after passing through another point (reference illustration below): Similar to the methodology described above, a single arrowhead overbar is used to denote a ray. Accordingly, the ray above may be denoted as:
https://mathworld.wolfram.com › Interval.html
Interval -- from Wolfram MathWorldIntervals involving infinity are also called rays or half-lines. If the finite point is included, it is a closed half-line or closed ray. If the finite point is not included, it is an open half-line or open ray.
https://math.libretexts.org › Bookshelves › Geometry › Euclidean_Plane_and_its_Relatives...
1.6: Half-lines and segments - Mathematics LibreTextsWe will denote by [PQ) [P Q) the half-line that starts at P P and contains Q Q. Formally speaking, [PQ) [P Q) is a subset of (PQ) (P Q) which corresponds to [0, ∞) [0, ∞) under an isometry f: (PQ) → R f: (P Q) → R such that f(P) = 0 f (P) = 0 and f(Q)> 0 f (Q)> 0.
https://onemathematicalcat.org › Math › Geometry_obj › angles_rays_segments.htm
Segments, Rays, Angles - OneMathematicalCat.orgA ray is a half-line, together with its endpoint. If a ray has endpoint $\,A\,,$ and if $\,B\,$ is any other point on the half-line, then the ray will be denoted by $\,\overrightarrow{AB}\,.$
https://proofwiki.org › wiki › Definition:Ray_(Order_Theory)
Definition:Ray (Order Theory) - ProofWikiThe following sets are called open rays or open half-lines: $\set {x \in S: a \prec x}$ (the strict upper closure of $a$), denoted $a^\succ$ $\set {x \in S: x \prec a}$ (the strict lower closure of $a$), denoted $a^\prec$.
https://mathworld.wolfram.com › Ray.html
Ray -- from Wolfram MathWorldWhen viewed as a vector, a ray is a vector AB^-> from a point A to a point B. In geometry, a ray is usually taken as a half-infinite line (also known as a half-line) with one of the two points A and B taken to be at infinity.
