Consider the Euclidean plane $\mathbb{R}^2$. A collineation on $\mathbb{R}^2$ is a bijective function $f$ from $\mathbb{R}^2$ to $\mathbb{R}^2$ such that the image of every line under $f$ is also a line. Does there exist a collineation which does not preserve betweenness? That is, there exists at least one triple of distinct points $(A,B,C)$ such that $B$ is between $A$ and $C$, but $f(B)$ is not between $f(A)$ and $f(C)$.
2026-03-24 02:39:23.1774319963
Is there a collineation which does not preserve betweenness?
19 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in EUCLIDEAN-GEOMETRY
- Visualization of Projective Space
- Triangle inequality for metric space where the metric is angles between vectors
- Circle inside kite inside larger circle
- If in a triangle ABC, ∠B = 2∠C and the bisector of ∠B meets CA in D, then the ratio BD : DC would be equal to?
- Euclidean Fifth Postulate
- JMO geometry Problem.
- Measure of the angle
- Difference between parallel and Equal lines
- Complex numbers - prove |BD| + |CD| = |AD|
- Find the ratio of segments using Ceva's theorem
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?