Chapter 12: Problem 5
Consider a square whose side-length is one unit. Select any five points from inside this square. Prove that at least two of these points are within \(\frac{\sqrt{2}}{2}\) units of each other.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 12: Problem 5
Consider a square whose side-length is one unit. Select any five points from inside this square. Prove that at least two of these points are within \(\frac{\sqrt{2}}{2}\) units of each other.
All the tools & learning materials you need for study success - in one app.
Get started for free
Is the set \(\theta=\left\\{(X,|X|): X \subseteq \mathbb{Z}_{5}\right\\}\) a function? If so, what is its domain and range?
\(\operatorname{Let} B=\left\\{2^{n}: n \in \mathbb{Z}\right\\}=\left\\{\ldots, \frac{1}{4}, \frac{1}{2}, 1,2,4,8, \ldots\right\\} .\) Show that the function \(f: \mathbb{Z} \rightarrow B\) defined as \(f(n)=2^{n}\) is bijective. Then find \(f^{-1}\).
Consider the function \(f: \mathbb{R}^{2} \rightarrow \mathbb{R}^{2}\) defined by the formula \(f(x, y)=\left(x y, x^{3}\right) .\) Is \(f\) injective? Is it surjective? Bijective? Explain.
Let \(f: A \rightarrow B\) be a function, and \(X \subseteq A .\) Prove or disprove: \(f\left(f^{-1}(f(X))\right)=f(X)\).
Given \(f: A \rightarrow B\) and subsets \(Y, Z \subseteq B,\) prove \(f^{-1}(Y \cap Z)=f^{-1}(Y) \cap f^{-1}(Z)\).
What do you think about this solution?
We value your feedback to improve our textbook solutions.