Explanation Given information: Let Q ∈ ℝ n × n is an orthogonal and upper triangular matrix. Proof: Basis: n = 1 Since Q 1 × 1 is orthogonal and upper triangular, it followsthat Q = [ ± 1 ] . Therefore, Q = [ q 1 ( 1 ) ] = [ ± 1 ] = [ ± e 1 ] ⇒ q 1 ( 1 ) = ± e 1 . Thus, the statement is true for n = 1 . Induction step: n ⇒ n + 1 Assume that the statement is true for n ∈ ℕ and prove that it is true for n + 1 . Since Q ( n + 1 ) × ( n + 1 ) = [ q 1 ( n + 1 ) q 2 ( n + 1 ) … q n ( n + 1 ) q n + 1 ( n + 1 ) ] , is an orthogonal matrix, its last column must satisfy the conditions 〈 q n + 1 ( n + 1 ) , q j ( n + 1 ) 〉 = 0 , j = 1 , 2 , ... , n , ‖ q n + 1 ( n + 1 ) ‖ = 1 , ( in ℝ n ) . Since Q ( n + 1 ) × ( n + 1 ) is also upper triangular matrix, if delete its last row and column, it will get an upper triangular and orthogonal matrix Q n × n = [ q 1 ( n ) q 2 ( n ) … q n ( n ) ]

Linear Algebra with Applications (9th Edition) (Featured Titles for Linear Algebra (Introductory))

9th Edition

ISBN: 9780321962218

Author: Steven J. Leon

Publisher: PEARSON

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Chapter 5.5, Problem 20E

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Toprove: qj=±ej, j=1,2,...n by using mathematical induction.

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Chapter 5.5, Problem 19E

Chapter 5.5, Problem 21E

Chapter 5 Solutions

Linear Algebra with Applications (9th Edition) (Featured Titles for Linear Algebra (Introductory))

Ch. 5.1 - Find the angle between the vectors v and w in each...Ch. 5.1 - For each pair of vectors in Exercise 1, find...Ch. 5.1 - For each of the following pairs of vectors x and...Ch. 5.1 - Let x and y be linearly independent vectors in 2....Ch. 5.1 - Find the point on the line y=2x that is closer to...Ch. 5.1 - Find the point on the line y=2x+1 that is closet...Ch. 5.1 - Find the distance from the point (1, 2) to the...Ch. 5.1 - In each of the following, find the equation of the...Ch. 5.1 - Find the equation of the plane that passes through...Ch. 5.1 - Find the distance from the point (1,1,1) to be...

Ch. 5.1 - Findthedistancefromthepoint (2,1,2) totheplane...Ch. 5.1 - If x=(x1,x2)T,y=(y1,y2)T, and z=(z1,z2)T...Ch. 5.1 - Prob. 13E Ch. 5.1 - Let x1,x2, and x3 be vectors in 3. If x1x2 and...Ch. 5.1 - Let A be a 22 matrix with linearly independent...Ch. 5.1 - If x and y are linearly independent vectors in 3,...Ch. 5.1 - Let x=(44 44) and y=(4221) Determine the angle...Ch. 5.1 - Let x and y be vectors in n and define p=xTyyTyy...Ch. 5.1 - Use the database matrix U from Application 1 and...Ch. 5.1 - Fivestudentsinanelementaryschooltakeaptitude tests...Ch. 5.1 - Let t be a fixed real number and let...Ch. 5.2 - For each of the following matrices, determine a...Ch. 5.2 - Let S be the subspace of 3 spanned by x=(1,1)T....Ch. 5.2 - a.Let S be the subspace of 3 spanned by the...Ch. 5.2 - Let S be the subspace of 4 spanned by...Ch. 5.2 - Let A be a 32 matrix with rank 2. Give geometric...Ch. 5.2 - Is it possible for a matrix to have the vector...Ch. 5.2 - Let aj be a nonzero column vector of an mn matrix...Ch. 5.2 - Let S be the subspace of n spanned by the vectors...Ch. 5.2 - If A is an mn matrix of rank r, what are the...Ch. 5.2 - Prob. 10E Ch. 5.2 - Prove: If A is an mn matrix and xn, then either...Ch. 5.2 - Let A be an mn matrix. Explain why the following...Ch. 5.2 - Let A bean mn matrix.Showthat If xN(ATA), then Ax...Ch. 5.2 - Let A be an mn matrix, B an nr matrix, and C=AB....Ch. 5.2 - Let U and V be subspaces of a vector space W. Show...Ch. 5.2 - Let A be an mn matrix of rank r and let...Ch. 5.2 - Let x and y be linearly independent vectors in n...Ch. 5.3 - Find the least squares solution of each of the...Ch. 5.3 - For each of your solutions x in Exercise 1:...Ch. 5.3 - For each of the following systems Ax=b, find...Ch. 5.3 - ForeachofthesystemsinExercise3,determinethe...Ch. 5.3 - Find the best least squares fit by a linear...Ch. 5.3 - Find the best least squares fit to the data in...Ch. 5.3 - Given a collection of points...Ch. 5.3 - The point (x,y) is the center of mass for the...Ch. 5.3 - LetAbean mnmatrixofranknandletP=A(ATA)1AT. (a)...Ch. 5.3 - LetAbean 85 matrixofrank3,andletbbea nonzero...Ch. 5.3 - Let P=A(ATA)1AT, where A is an mn matrixof rank n....Ch. 5.3 - Show that if (AIO A T )( x r)=(b0) then x is a...Ch. 5.3 - Let and let be a solution of the leastsquares...Ch. 5.3 - Find the equation of the circle that gives the...Ch. 5.3 - Prob. 15E Ch. 5.4 - Let x=(1,1,1,1)T and y=(1,1,5,3)T. Showthat xy....Ch. 5.4 - Let x=(1,1,1,1)T and y=(8,2,2,0)T....Ch. 5.4 - Use equation (1) with weight vector w=(14,12,14)T...Ch. 5.4 - Given A=(122102311) and B=( 411 3321 2 2)...Ch. 5.4 - Show that equation (2) defines an inner product on...Ch. 5.4 - Showthattheinnerproductdefinedbyequation(3)...Ch. 5.4 - In C[0,1], with inner product defined by (3),...Ch. 5.4 - In C[0,1], with inner product defined by (3),...Ch. 5.4 - In C[,] with inner product defined by (6), show...Ch. 5.4 - Show that the functions x and x2 are orthogonal in...Ch. 5.4 - In P5 with inner product as in Exercise 10 and...Ch. 5.4 - If V is an inner product space, show that v=v,v...Ch. 5.4 - Show that x1=i=1n|xi| defines a norm on n.Ch. 5.4 - Show that x=max1in|xi| defines a norm on n.Ch. 5.4 - Compute x1,x2, and x for each of the following...Ch. 5.4 - Let x=(5,2,4)T and y=(3,3,2)T. Compute xy1,xy2,...Ch. 5.4 - Prob. 17E Ch. 5.4 - Prob. 18E Ch. 5.4 - In n with inner product x,y=xTy Derive a formula...Ch. 5.4 - Prob. 20E Ch. 5.4 - Let xn. Show that xx2.Ch. 5.4 - Prob. 22E Ch. 5.4 - Prob. 23E Ch. 5.4 - Prob. 24E Ch. 5.4 - Prob. 25E Ch. 5.4 - Prove that, for any u and v in an inner...Ch. 5.4 - The result of Exercise 26 is not valid for norms...Ch. 5.4 - Determine whether the following define norms on...Ch. 5.4 - Let xn and show that x1nx x2nx Give examples of...Ch. 5.4 - Sketch the set of points (x1,x2)=xT in 2 such that...Ch. 5.4 - LetK bean nn matrixoftheform K=(1 c c c0s sc sc00...Ch. 5.4 - Thetraceofan nn matrixC, denoted tr(C), isthe sum...Ch. 5.4 - Consider the vector space n with inner product...Ch. 5.5 - Which of the following sets of vectors form an...Ch. 5.5 - Let u1=( 1 3 2 1 3 2 4 3 2 ),u2=( 2 3 2 3 1 3...Ch. 5.5 - Let S be the subspace of 3 spanned by the vectors...Ch. 5.5 - Let be a fixed real number and let x1=( cos sin)...Ch. 5.5 - Let u1 and u2 form an orthonormal basis for 2 and...Ch. 5.5 - Let {u1,u2,u3} be an orthonormal basis for an...Ch. 5.5 - Let {u1,u2,u3} beanorthonormalbasisforaninner...Ch. 5.5 - The functions cosx and sinx form an orthonormal...Ch. 5.5 - The set S={12,cosx,cos2x,cos3x,cos4x}...Ch. 5.5 - Prob. 10E Ch. 5.5 - Prob. 11E Ch. 5.5 - If Q is an nn orthogonal matrix and x and y are...Ch. 5.5 - Prob. 13E Ch. 5.5 - Prob. 14E Ch. 5.5 - Let Q be an orthogonal matrix and let d=det(Q)....Ch. 5.5 - Show that the product of two orthogonal matrices...Ch. 5.5 - Prob. 17E Ch. 5.5 - Prob. 18E Ch. 5.5 - Prob. 19E Ch. 5.5 - Prob. 20E Ch. 5.5 - Let A=( 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 ) Show...Ch. 5.5 - Prob. 22E Ch. 5.5 - Prob. 23E Ch. 5.5 - Let A be an mn matrix, let P be the projection...Ch. 5.5 - Let P be the projection matrix corresponding to a...Ch. 5.5 - Prob. 26E Ch. 5.5 - Let v be a vector in an inner product space V...Ch. 5.5 - Let v be a vector in an inner product space V and...Ch. 5.5 - Given the vector space C[1,1] with inner product...Ch. 5.5 - Consider the inner product space C[0,1] with inner...Ch. 5.5 - Prob. 31E Ch. 5.5 - Find the best least squares approximation to...Ch. 5.5 - Let {x1,x2,...,xk,xk+1,...,xn} be an orthonormal...Ch. 5.5 - Prob. 34E Ch. 5.5 - Prob. 35E Ch. 5.5 - A(real or complex)scalar u is said to bean nth...Ch. 5.5 - Prob. 37E Ch. 5.5 - Prob. 38E Ch. 5.6 - For each of the following, use the GramSchmidt...Ch. 5.6 - Factor each of the matrices in Exercise 1 into a...Ch. 5.6 - Giventhebasis {(1,2,2)T,(1,2,1)T} for 3, use the...Ch. 5.6 - Consider the vector space C[1,1] with innerproduct...Ch. 5.6 - Let A=(211121) and b=( 126 18) Use the GramSchmidt...Ch. 5.6 - Repeat Exercises 5 using A=(3 14202) and b=(0 20...Ch. 5.6 - Given x1=12(1,1,1,1)T and x2=16(1,1,3,5)T, verify...Ch. 5.6 - Use the GramSchmidt process to find an orthonormal...Ch. 5.6 - Repeat Exercise 8 using the modified GramSchmidt...Ch. 5.6 - Let A be an m2 matrix. Show that if both the...Ch. 5.6 - LetAbean m3 matrix.LetQRbetheQRfactorization...Ch. 5.6 - What will happen if the GramSchmidt process is...Ch. 5.6 - Let Abeanmn matrix of rank n and let bm. Show that...Ch. 5.6 - Let U be an m-dimensional subspace of n and let V...Ch. 5.6 - (Dimension Theorem) Let U and V be subspaces of n....Ch. 5.7 - Use the recursion formulas to calculate (a) T4,T5...Ch. 5.7 - Prob. 2E Ch. 5.7 - Prob. 3E Ch. 5.7 - Prob. 4E Ch. 5.7 - Prob. 5E Ch. 5.7 - Prob. 6E Ch. 5.7 - Prob. 7E Ch. 5.7 - Prob. 8E Ch. 5.7 - Prob. 9E Ch. 5.7 - Prove each of the following....Ch. 5.7 - Givenafunction f(x) thatpassesthroughthepoints...Ch. 5.7 - Prob. 12E Ch. 5.7 - Prob. 13E Ch. 5.7 - Prob. 14E Ch. 5.7 - Let x1,x2,...,xn be distinct point in the interval...Ch. 5.7 - Prob. 16E Ch. 5.7 - Prob. 17E Ch. 5 - Set x=[0:4,4,1,1] and y=ones(9,1) Use the MATLAB...Ch. 5 - Prob. 2E Ch. 5 - Prob. 3E Ch. 5 - (Least Squares Circles) The parametric equations...Ch. 5 - Prob. 5E Ch. 5 - Prob. 1CTA Ch. 5 - If x and y are unit vectors in n and |xTy|=1, then...Ch. 5 - If U, V, and W are subspaces of 3 and if UV and...Ch. 5 - It is possible to find a nonzero vector y in the...Ch. 5 - Prob. 5CTA Ch. 5 - Prob. 6CTA Ch. 5 - If N(A)={0}, then the system Ax=b will have a...Ch. 5 - Prob. 8CTA Ch. 5 - Prob. 9CTA Ch. 5 - Prob. 10CTA Ch. 5 - Prob. 1CTB Ch. 5 - Prob. 2CTB Ch. 5 - Prob. 3CTB Ch. 5 - Let A be a 75 matrix with rank equal to 4 and let...Ch. 5 - Letxandybevectorsin n andletQbean nn orthogonal...Ch. 5 - Let S be the two-dimensional subspace of 3 spanned...Ch. 5 - Prob. 7CTB Ch. 5 - Prob. 8CTB Ch. 5 - Prob. 9CTB Ch. 5 - Prob. 10CTB Ch. 5 - The functions cosx and sinx are both unit vectors...Ch. 5 - Prob. 12CTB

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Toprove : q j = ± e j , j = 1 , 2 , ... n by using mathematical induction.

Solution Summary: The author proves that Qin Rntimes 1 is an orthogonal and upper triangular matrix by mathematical induction.

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Toprove: qj=±ej, j=1,2,...n by using mathematical induction.

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Chapter 5 Solutions