Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1:...

33
6.1-6.4 Key Exercises Math 2331 – Linear Algebra 6.1-6.4 Orthogonality Key Exercises Jiwen He Department of Mathematics, University of Houston [email protected] math.uh.edu/jiwenhe/math2331 Jiwen He, University of Houston Math 2331, Linear Algebra 1 / 33

Transcript of Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1:...

Page 1: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises

Math 2331 – Linear Algebra6.1-6.4 Orthogonality

Key Exercises

Jiwen He

Department of Mathematics, University of Houston

[email protected]/∼jiwenhe/math2331

Jiwen He, University of Houston Math 2331, Linear Algebra 1 / 33

Page 2: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

6.1 Inner Product, Length & Orthogonality

Key Exercises 19–20, 27–31

The general material on orthogonal complements is essentialfor later work.

Key Exercises: 19–20, 27–31. Exercies 27–31 concern factsthat are needed later

Jiwen He, University of Houston Math 2331, Linear Algebra 2 / 33

Page 3: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 3 / 33

Page 4: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 4 / 33

Page 5: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 5 / 33

Page 6: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 6 / 33

Page 7: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 7 / 33

Page 8: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 8 / 33

Page 9: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 9 / 33

Page 10: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

6.2 Orthogonal Sets

Key Exercises 13–14, 23–24, 26–30

The nonsquare matrices in Theorems 6 and 7 are needed forthe QR factorization in Section 6.4.

The term orthogonal matrix applies only to certain squarematrices.

Key Exercises: 13–14, 23–24, 26–30. Exercies 13–14 preparefor Section 6.3.

Jiwen He, University of Houston Math 2331, Linear Algebra 10 / 33

Page 11: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 11 / 33

Page 12: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 12 / 33

Page 13: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 13 / 33

Page 14: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 14 / 33

Page 15: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 15 / 33

Page 16: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 16 / 33

Page 17: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 17 / 33

Page 18: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 18 / 33

Page 19: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 19 / 33

Page 20: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

6.3 Orthogonal Projections

Key Exercises 19–24

Theorem 9 is needed for the Gram-Schmidt process.

Key Exercises: 19–24. Exercies 19–20 lead naturally into theGram-Schmidt process.

Jiwen He, University of Houston Math 2331, Linear Algebra 20 / 33

Page 21: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 21 / 33

Page 22: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 22 / 33

Page 23: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 23 / 33

Page 24: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 24 / 33

Page 25: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 25 / 33

Page 26: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 26 / 33

Page 27: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

6.4 The Gram-Schmidt Process

Key Exercises 17–21,23

The QR factorization encapsulates the essential outcome ofthe Gram-Schmidt process, just as the LU factorizationdescribes the result of a row reduction process.

For practical use of linear algebra, the factorizations are moreimportant than the algorithms that produce them.

Key Exercises: 17–21, 23.

Jiwen He, University of Houston Math 2331, Linear Algebra 27 / 33

Page 28: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 28 / 33

Page 29: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

All vectors are in Rn. Mark each statement True or False. Justifyeach answer.

Jiwen He, University of Houston Math 2331, Linear Algebra 29 / 33

Page 30: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 30 / 33

Page 31: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 31 / 33

Page 32: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 32 / 33

Page 33: Math 2331 { Linear Algebrajiwenhe/math2331/lectures/sec6_1-4_ex.p… · 6.1-6.4 Key Exercises 6.1: 19{316.2: 13{306.3: 19{246.4: 17{23 6.4 The Gram-Schmidt Process Key Exercises 17{21,23

6.1-6.4 Key Exercises 6.1: 19–31 6.2: 13–30 6.3: 19–24 6.4: 17–23

Jiwen He, University of Houston Math 2331, Linear Algebra 33 / 33