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  • ...to any loose collection of objects or entities -- of any nature -- as a ''set''. ...lly, whether the items are arranged in a box or piled up on the counter. A set of encyclopedia consists of books that can be arranged alphabetically or ch
    151 KB (25,679 words) - 17:09, 20 February 2019
  • ...ack to our the example of five boys that form a set and another set is the set of these four balls: We can form a new set that contains all the elements of the two sets.
    142 KB (23,566 words) - 02:01, 23 February 2019
  • '''Definition.''' Given an arbitrary set $X$, a collection $\tau$ of subsets of $X$ is called a ''topology<!--\index Of course, instead, we can, and did, start with the set of all neighborhoods $\gamma$ in $X$ and then define open sets as ones wher
    27 KB (4,693 words) - 02:35, 20 June 2019
  • '''Theorem 1.4.3''' The solution set of a homogeneous linear equation If $a_1=a_2=a_3=0$, the the equation turns into $0 = 0$, and the solution set is ${\bf R}^3$.
    26 KB (3,993 words) - 19:48, 26 August 2011
  • '''Theorem 1.4.3''' The solution set of a homogeneous linear equation ...''a''<sub>3</sub> = 0, the the equation turn into 0 = 0, and the solution set is '''R<sup>3</sup>'''.
    27 KB (4,667 words) - 01:07, 19 February 2011
  • '''Definition.''' Suppose $X$ is any set. A collection $\gamma$ of subsets of $X$ satisfying the properties of: ...r any neighborhoods $U, V\in \gamma$ and any point $x\in U\cap V$ in their intersection, there is a neighborhood $W\in \gamma$ of $x$ such that $W \subset U \cap V
    16 KB (2,758 words) - 00:19, 25 November 2015
  • ...s produce intervals and, conversely, every interval in the $x$-axis is its intersection with a disk: ...$X$ with basis $\gamma$ will acquire its own collection $\gamma _A$ as the set of all of its intersections with the elements of $\gamma$:
    34 KB (6,089 words) - 03:50, 25 November 2015
  • This set is called a ''realization''<!--\index{realization}--> of the graph which is This data set is called a ''simplicial complex''<!--\index{simplicial complex}--> (or som
    31 KB (5,219 words) - 15:07, 2 April 2016
  • ...s a ''constant function'', i.e., for some specified element $b$ of $Y$, we set: So, for our set $X$ of boys, we have a special function $G$ from $X$ to $X$ (and another fr
    143 KB (24,052 words) - 13:11, 23 February 2019
  • Generally, for any two sets $X$ and $Y$, their product set is defined as the set of ordered pairs taken from $X$ and $Y$: ...s to demonstrate how we can define the algebraic operations on the product set ${\bf R} \times {\bf R}$ in terms of the operations on either copy of ${\bf
    44 KB (7,951 words) - 02:21, 30 November 2015
  • ...on of two intervals is the sum of the two lengths minus the lengths of the intersection: ...the union of two regions is the sum of the two areas minus the area of the intersection:
    103 KB (18,460 words) - 01:01, 13 February 2019
  • ...if we don't even have a cell complex but only a topological space, i.e., a set with a collection of open subsets? What topological spaces are polyhedra? ...pen sets have non-empty ''pairwise'' intersections but the only ''triple'' intersection is empty. Why is this important? Notice the pattern:
    30 KB (5,172 words) - 21:52, 26 November 2015
  • ...ical issues, let's take care of the underlying ''sets''<!--\index{quotient set}-->. Now, '''notation''' for the quotient set is:
    26 KB (4,538 words) - 23:15, 26 November 2015
  • This set is defined explicitly and is independent from the existence of the inverse ...appear implicitly in many areas of mathematics. For example, the solution set of the equation $f(x) = b$ is $f^{-1}(\{b\})$. In particular, the kernel of
    42 KB (7,138 words) - 19:08, 28 November 2015
  • '''Definition.''' Suppose $X$ is any set. Any collection $\gamma$ of subsets of $X$ satisfying properties: ...r any neighborhoods $U, V\in \gamma$ and any point $x\in U\cap V$ in their intersection, there is a neighborhood $W\in \gamma$ of $x$ such that $W \subset U \cap V
    11 KB (2,025 words) - 14:57, 2 August 2014
  • Suppose the set of all [[Neighborhoods and topologies|neighborhoods]] $\gamma$ in $X$ is gi [[Image:open set definition.png|500px|center]]
    4 KB (625 words) - 01:55, 1 October 2013
  • ...dex{locally Euclidean space}--> $n$ if for every $x\in X$ there is an open set $U$ such that $x\in U$ and there is a homeomorphism $h:{\bf R}^n \to U$. Th ...n we would simply consider the standard “local” basis at $a$, which is the set of all open $\epsilon$-balls around $a$:
    51 KB (8,919 words) - 01:58, 30 November 2015
  • '''Definition.''' The ''graph'' of a function of one variable $z=f(x)$ is the set of all points in ${\bf R}^{2}$ of the form $(x,f(x))$. ...inition.''' The ''graph'' of a function of two variables $z=f(x,y)$ is the set of all points in ${\bf R}^{3}$ of the form $(x,y,f(x,y))$.
    97 KB (17,654 words) - 13:59, 24 November 2018
  • '''Example.''' Suppose $A$ and $B$ are path-connected and $a$ is in the intersection. If $P$ and $Q$ belong to the union, find a path from $P$ to $a$, from $a$ *Set up, but do not solve, a system of linear equations for the following proble
    46 KB (8,035 words) - 13:50, 15 March 2018
  • We set up two functions, for the location and the altitude. Then their composition ...t_1$ your car is the same distance from the intersection as it is past the intersection at time $t_2$. Then the $\Delta S=0$! So, the reading ''can'' be off by a l
    82 KB (14,116 words) - 19:50, 6 December 2018
  • The idea is to use this set-up to produce a correspondence: The idea is to use this set-up to produce a correspondence:
    100 KB (16,148 words) - 20:04, 18 January 2017
  • A function defined on a ray in the set of integers, $\{p,p+1,...\}$, is called an ''infinite sequence'', or simply The last option is used when we treat the sequence as a ''set''.
    64 KB (10,809 words) - 02:11, 23 February 2019
  • For the background see [[Introduction to point-set topology]]. Given a set $A$ in $X$,
    4 KB (703 words) - 01:55, 1 October 2013
  • '''Dimension 1:''' When is a level set of $f \colon {\bf R} \rightarrow {\bf R}$ a $0$-manifold? Then we are looking at the intersection of the graph of $f$ and the plane $z=A$, around the point $(a,A)$. Since $f
    9 KB (1,542 words) - 19:58, 21 January 2014
  • In other words, we find the intersection of the tangent line with the $x$-axis: The equation, which is ''linear'', is easy to solve. The point of intersection is
    59 KB (10,063 words) - 04:59, 21 February 2019
  • ...a line on the plane. Then the solution $(x,y)=(4,2)$ is the point of their intersection: ...equations represent two planes in ${\bf R}^3$. The solution is then their intersection:
    113 KB (18,750 words) - 02:33, 10 December 2018
  • #redirect[[Introduction to point-set topology]] Our interest is mainly is algebraic topology. Consequently, point-set topology will be limited to that of the [[euclidean space]], "nice" subsets
    7 KB (1,207 words) - 13:01, 12 August 2015
  • A '''simplicial complex''' <math>\mathcal{K}</math> is a set of [[Simplex|simplices]] that satisfies the following conditions: :2. The non-empty [[Set intersection|intersection]] of any two simplices <math>\sigma_1, \sigma_2 \in \mathcal{K}</math> is a
    27 KB (4,329 words) - 16:02, 1 September 2019
  • ...s. The height at the end of the flight is $y_1=0$, so to find the time, we set $y=200-16t^2=0$ and solve for $t$: ...ordinates have make sense. Then, we can choose the domain of $F$ to be the intersection of the domains of $f$ and $g$.
    76 KB (13,017 words) - 20:26, 23 February 2019
  • Prove that the [[intersection]] of a finite collection of [[open set]]s is open. ...e intersection of these neighborhoods. It will lie inside the intersection set.
    506 bytes (79 words) - 14:43, 23 February 2011
  • *a ''circle'' on the plane is defined to be the set of all point a given distance away from its center; *a ''sphere'' in the space is defined to be the set of all point a given distance away from its center.
    113 KB (19,680 words) - 00:08, 23 February 2019
  • *[[Can a set to be both open and closed? ]] *[[Intersection of any collection of closed sets is closed ]]
    9 KB (1,553 words) - 20:10, 23 October 2012
  • ...persistence and can be removed when the threshold for acceptable noise is set. ...$ defined on a rectangle $R$. Then, given a threshold $r$, its lower level set $f^{-1}((-\infty,r))$ can be thought of as a binary image on $R$. Each blac
    45 KB (7,255 words) - 03:59, 29 November 2015
  • Now, an example of an especially “nice” set is ...ion $1$, this is simply a closed interval, yet functions defined on such a set won't fit into the last definition of continuity.
    17 KB (2,946 words) - 04:51, 25 November 2015
  • [[Image:path-connected set.jpg|right]] '''Exercise.''' Apply the same proof to show that any [[convex set]] is path-connected (think of a box, a square, a 3d cylinder, etc).
    34 KB (5,636 words) - 23:52, 7 October 2017
  • ...R}^n {\rightarrow} {\bf R}$, then for each $c {\in} {\bf R}$ the ''[[level set]]'' relative to $c$ of $f$ is What would be a level set that is not a curve, but that isn't a maximum or a minimum?
    28 KB (4,769 words) - 19:42, 18 August 2011
  • ...\bf R}^n \rightarrow {\bf R}$, then for each $c \in {\bf R}$ the ''[[level set]]'' relative to $c$ of $f$ is What would be a level set that is not a curve, but that isn't a maximum or a minimum?
    2 KB (400 words) - 20:29, 28 August 2011
  • *$x\in X\quad$ “$x$ belongs to set $X$” or “$x$ is an element of $X$”; *$x\not\in X\quad$ “$x$ does not belongs to set $X$” or “$x$ is not an element of $X$”;
    2 KB (438 words) - 22:34, 22 June 2019
  • #Prove that the set of all non-zero rational numbers, $\mathbf{Q}\backslash \{0\},$ is closed u #Prove that the intersection of two subspaces is always a subspace.
    4 KB (538 words) - 20:28, 9 September 2011
  • *[http://users.marshall.edu/~saveliev/Teaching/Fall17/math231/set01.pdf Set 1] *[http://users.marshall.edu/~saveliev/Teaching/Fall17/math231/set2.pdf Set 2]
    10 KB (1,596 words) - 13:34, 27 November 2017
  • ...rics of polytopes, triangulations, combinatorial fixed point theorems, set intersection theorems, combinatorial convexity, lattice point counting, and tropical geo ...essible to beginning math majors. Such a course should have a very limited set of prerequisites, mostly an appropriate level of "mathematical maturity". I
    8 KB (1,122 words) - 02:52, 24 October 2011
  • Because it's not independent from the rest (and we want to make the set of axioms as short as possible). Indeed we derive it: '''Definition:''' A ''vector space'' is a set $V$, where two operations are defined:
    14 KB (2,238 words) - 17:38, 5 September 2011
  • Let $V$ be the set of all functions $f \colon {\bf R} \rightarrow {\bf R}$. But, we have to ask: is the set [[closed under operations|closed]] under these operations?
    14 KB (2,471 words) - 21:48, 5 September 2011
  • *$U={\bf R}^N$ with basis being the set of all vectors and *$W={\bf R}^n$ with basis being the set of all edges.
    13 KB (2,067 words) - 01:11, 12 September 2011
  • The open sets have non-empty pairwise intersections but the intersection of all three is empty. So what? Observe: *$n$-simplices corresponding to non-empty intersection of $n$ elements of the cover.
    8 KB (1,389 words) - 13:35, 12 August 2015
  • Furthermore, we connect the centers of the adjacent rods using an extra set of rods (and hinges) that form a new, Hodge-dual, complex $K^{\star}$. ...closed under the operations of complement, countable union, and countable intersection. If, furthermore, $K$ has a volume function, the function $\mu :\Sigma \to
    20 KB (3,354 words) - 17:37, 30 November 2015
  • We use the following '''notation''' for the quotient set: As we know, it is simply the set of all equivalence classes of this equivalence relation:
    13 KB (2,270 words) - 22:14, 18 February 2016
  • i.e., the set of equivalence classes: ...relation $~$ on it, the corresponding ''quotient set'' $X/_{\sim}$ is the set of its equivalence classes:
    3 KB (464 words) - 19:36, 31 October 2012
  • Furthermore, we connect the centers of the adjacent rods using an extra set of rods (and hinges) that form a new, Hodge-dual, complex $K^{\star}$. ...closed under the operations of complement, countable union, and countable intersection. If, furthermore, $K$ has a volume function, the function $\mu :\Sigma \to
    21 KB (3,445 words) - 13:53, 19 February 2016
  • ##The intersection of two linear subspaces is a linear subspace. ##The empty set is a linear subspace.
    4 KB (674 words) - 02:48, 22 August 2011

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