
Math 221  Linear Algebra  Reading Assignments
December 1999

Be sure to check back, since these may change.
(Last modified:
Wednesday, August 18, 1999,
3:35 PM )
I'll use Maple syntax for mathematical notation on this page.
All numbers indicate sections from Linear Algebra and Its Applications by David Lay.
For December 2
Section 6.3 Orthogonal Projections
 To read : Through Example 3
 Be sure to understand : Figure 2 and the statement of the Best Approximation Theorem
Email Subject Line : Math 221 12/2 Your Name
Reading Questions :
Let y=(1,2,3) in R^{3} and let W be the xzplane.
 What is the orthogonal projection of y onto W?
 Is there a point in W that is closer to y than the orthogonal projection you just found? Why or why not?
For December 7
Section 6.5 Least Squares Problems
 To read : Through Example 3
 Be sure to understand :
The definition of a general least squares problem and the statement of Theorem 13
Email Subject Line : Math 221 12/7 Your Name
Reading Questions :
 In your own words, what is the point of the section? (Don't just quote the text.)
 Does every system Ax=b have a least squares solution? If it exists, is it unique? Explain.
For December 9
Section 6.6 Applications to Linear Models
 To read : Through Example 3
 Be sure to understand :
Examples 1, 2, and 3
Email Subject Line : Math 221 12/9 Your Name
Reading Questions :
 In your own words, what is the point of the section? (Don't just quote the text.)
 What is surprising about being able to use linear algebra to solve Example 2?
For December 14
The REALLY BIG PICTURE. Last day of class. No Reading Assignment.
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