21-241 Matrix Algebra


Homework #1:

Exercises: Due Thursday, May 20

Section 1.1:  2, 8, 14, 15, 20, 25, 33, 34
Section 1.2:  3, 7, 12, 14, 16, 23, 29, 31
Section 1.3:  3, 7, 10, 12, 13, 17, 22
 

Homework #2:

Exercises: Due Tuesday, May 25

Section 1.4:  10, 12, 15, 19, 35
Section 1.5:  2, 6, 16, 29-32, 35
Section 1.6:  4, 6, 12
 

Homework #3:

Exercises: Due Wednesday, May 26

Section 1.7:  3, 6, 12, 20, 23, 28, 31, 33
Section 1.8:  4, 10, 12, 15, 17, 18, 25, 31
Section 1.9:  3, 6, 7, 9, 13, 17, 25, 29-31
 

Homework #4:

Exercises: Due Tuesday, June 1

Section 2.1:  9, 10, 13, 14, 23, 24, 27, 28
Section 2.2:  2, 7, 13-16, 20, 31, 33
 

Homework #5:

Exercises: Due Thursday, June 3

Section 2.3:  7, 14, 18, 19, 22, 28, 33
Section 2.7:  2, 5, 7, 14, 17, 18
Problem A: Refer to the triangle in Exercise 2.7.2. Suppose you wish to rotate this triangle 60 degrees with respect to the point (6,8). Draw a sketch which shows the initial position of the triangle, and illustrates approximately where the triangle would end up after this transformation. (You do not need to try and guess the coordinates of the new vertices -- just illustrate their approximate positions.) Then use the matrix you found in Exercise 2.7.7 to perform this rotation. This will give you the new vertices. Finally, draw another sketch which illustrates the transformation.

Homework #6:

Exercises: Due Tuesday, June 8

Section 2.8:  3, 6, 11-15, 24, 26, 27
Section 2.9:  1, 5, 12, 14, 16, 20
Section 3.1:  7, 11, 23, 37, 38 

Homework #7:

Exercises: Due Thursday, June 10

Section 3.2:  1, 8, 13, 23, 26, 31, 34-36
Section 5.1:  6, 10, 16-20, 27, 29, 30, 33
Section 5.2:  1, 8, 10, 17, 18, 20
 

Homework #8:

Exercises: Due Tuesday, June 15

Section 5.3:  1, 3, 15, 18, 24, 27, 31
Section 5.5:  5
Problem A:  Find all real and complex eigenvalues of the 3 X 3 matrix A below, and for each eigenvalue, find a corresponding eigenvector. 
                [1   1  -1]
        A   =   [0   1   0]
                [1   0   1]
Problem B:  Find all real and complex roots of the polynomial
    
                     x^3 + x^2 + 17x - 87
Hints:  First look for real integer roots by substituting values such as 0, 1, -1, 2, -2, etc., into the polynomial, in hopes that you will find a "nice" root r.  If you find one, then you know that the polynomial can be factored as follows:
                    (x - r) (x^2 + ax + b)
By multiplying these factors, you can determine the appropriate values for a and b.  Finally, you can find the roots of the quadratic factor, using the quadratic formula if necessary.
Problem C:  Find all real and complex eigenvalues of the 4 X 4 matrix A below, and for each eigenvalue, find a corresponding eigenvector. 
                [1   -1   1  -1]
        A   =   [1    1   1   1]
                [0    0   1   1]
                [0    0   1   1]
Section 5.6:  3, 10, 12, 14, 15, 17ab

Homework #9:

Exercises: Due Thursday, June 17

Section 6.1:  2, 3, 6, 8, 9, 11, 14-18, 28
Section 6.2:  2, 3, 7, 10, 12, 13, 17, 20, 22, 25, 28  
 

Homework #10:

Exercises: Due Monday, June 21

Section 6.3:  1, 5, 9, 12, 13, 16, 17
Section 6.4:  3, 7, 11, 12
 

Homework #11:

Exercises: Due Wednesday, June 23

Section 6.5: 2, 5, 11, 19, 20, 22, 25
Section 6.6:  2 (include a sketch of the data points and the least-squares line), 7 (designated with [M] but not bad; include a sketch of the data points and the least-squares parabola approximating the data.  You may use technology to determine what this graph looks like, or use algebraic methods, such as completing the square, to determine the location of the parabola's vertex.)
Section 7.1:  1-12, 16, 18, 21, 24, 27-30
 

Homework #12:

Exercises: Due Friday, June 25

Section 7.2:  1, 5, 8, 12, 19
Section 7.3:  5, 8, 10, 11
Section 7.4:  1-4, 11, 13, 15-17