/*! 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} Q15E A k-pyramid \({P^k}\) is the con... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A k-pyramid \({P^k}\) is the convex hull of a \(\left( {k - {\bf{1}}} \right)\)-polytope Q and a point \({\bf{x}} \notin {\bf{aff}}\,\,Q\). Find a formula for each of the following in terms of \({f_j}\left( Q \right),j = {\bf{0}},......,n - {\bf{1}}\).

a. The number of vertices of \({P^n}\): \({f_{\bf{0}}}\left( {{P^n}} \right)\).

b. The number of k-faces of \({P^n}\): \({f_k}\left( {{P^n}} \right)\), for \({\bf{1}} \le k \le n - {\bf{2}}\)

c. The number of \(\left( {n - {\bf{1}}} \right)\) dimensional facets of \({P^n}\): \({f_{n - {\bf{1}}}}\left( {{P^n}} \right)\).

Short Answer

Expert verified

a. \({f_0}\left( {{P^n}} \right) = {f_0}\left( Q \right) + 1\)

b. \({f_k}\left( {{P^n}} \right) = {f_k}\left( Q \right) + {f_{k - 1}}\left( Q \right)\)

c. \({f_{n - 1}}\left( {{P^n}} \right) = {f_{n - 2}}\left( Q \right) + 1\)

Step by step solution

01

Find the formula for part (a)

As k pyramid is the convex hull of \(\left( {k - 1} \right)\) polytope Q and \(x \notin {\rm{aff}}\,\,Q\), then the formula for vertices of \({P_n}\) is shown below:

\({f_0}\left( {{P^n}} \right) = {f_0}\left( Q \right) + 1\)

Thus, the formula is \({f_0}\left( {{P^n}} \right) = {f_0}\left( Q \right) + 1\).

02

Find the formula for part (b)

The number of k-faces of \({P_n}\) is given by the formula as shown below:

\({f_k}\left( {{P^n}} \right) = {f_k}\left( Q \right) + {f_{k - 1}}\left( Q \right)\)

Thus, the formula is \({f_k}\left( {{P^n}} \right) = {f_k}\left( Q \right) + {f_{k - 1}}\left( Q \right)\).

03

Find the formula for part (c)

The number of \(n - 1\) dimensional faces of \({P^n}\) is given by the formula\({f_{n - 1}}\left( {{P^n}} \right) = {f_{n - 2}}\left( Q \right) + 1\).

Thus, the formula is \({f_{n - 1}}\left( {{P^n}} \right) = {f_{n - 2}}\left( Q \right) + 1\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

In Exercises 21-26, prove the given statement about subsets A and B of \({\mathbb{R}^n}\), or provide the required example in \({\mathbb{R}^2}\). A proof for an exercise may use results from earlier exercises (as well as theorems already available in the text).

25. \({\mathop{\rm aff}\nolimits} \left( {A \cap B} \right) \subset \left( {{\mathop{\rm aff}\nolimits} A \cap {\mathop{\rm aff}\nolimits} B} \right)\)

Question 1: Given points \({{\mathop{\rm p}\nolimits} _1} = \left( {\begin{array}{*{20}{c}}1\\0\end{array}} \right),{\rm{ }}{{\mathop{\rm p}\nolimits} _2} = \left( {\begin{array}{*{20}{c}}2\\3\end{array}} \right),\) and \({{\mathop{\rm p}\nolimits} _3} = \left( {\begin{array}{*{20}{c}}{ - 1}\\2\end{array}} \right)\) in \({\mathbb{R}^2}\), let \(S = {\mathop{\rm conv}\nolimits} \left\{ {{{\mathop{\rm p}\nolimits} _1},{{\mathop{\rm p}\nolimits} _2},{{\mathop{\rm p}\nolimits} _3}} \right\}\). For each linear functional \(f\), find the maximum value \(m\) of \(f\), find the maximum value \(m\) of \(f\) on the set \(S\), and find all points x in \(S\) at which \(f\left( {\mathop{\rm x}\nolimits} \right) = m\).

a.\(f\left( {{x_1},{x_2}} \right) = {x_1} - {x_2}\)

b. \(f\left( {{x_1},{x_2}} \right) = {x_1} + {x_2}\)

c. \(f\left( {{x_1},{x_2}} \right) = - 3{x_1} + {x_2}\)

Explain why a cubic Bezier curve is completely determined by \({\mathop{\rm x}\nolimits} \left( 0 \right)\), \(x'\left( 0 \right)\), \({\mathop{\rm x}\nolimits} \left( 1 \right)\), and \(x'\left( 1 \right)\).

Question: In Exercises 15-20, write a formula for a linear functional f and specify a number d, so that \(\left) {f:d} \right)\) the hyperplane H described in the exercise.

Let H be the plane in \({\mathbb{R}^{\bf{3}}}\) spanned by the rows of \(B = \left( {\begin{array}{*{20}{c}}{\bf{1}}&{\bf{4}}&{ - {\bf{5}}}\\{\bf{0}}&{ - {\bf{2}}}&{\bf{8}}\end{array}} \right)\). That is, \(H = {\bf{Row}}\,B\).

Question: 1. Let Lbe the line in \({\mathbb{R}^{\bf{2}}}\) through the points \(\left( {\begin{array}{*{20}{c}}{ - {\bf{1}}}\\{\bf{4}}\end{array}} \right)\) and \(\left( {\begin{array}{*{20}{c}}{\bf{3}}\\{\bf{1}}\end{array}} \right)\). Find a linear functional f and a real number d such that \(L = \left( {f:d} \right)\).

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.