Due: 28 September 2011
Math 1090-002
23 September 2011
Sections 2.1 & 2.2 Homework
Instructions: Complete the following problems in the space provided. Please
show your work; write down enough so that a classmate could follow the steps
you’ve taken to arrive at the solution.

1

A= 0
−2
"
F =
−7


6 
5
2
−2
−2
29
"
5
3
−7
1
−1
4
1
0
0

G= 0
1
0
0

0 
1
B=

#
#
"
C=


−1

P = 0
1
1. What is the size of each of the above matrices?
1
0
0
1
#
D=
2
11
2
4
−3
−5

8 
7
(4 points)
B:
C:
D:
F:
G:
P:
Q:
0
−5
10
i

7
A:
1
h
Q=
h
5
−15
3
i
2. Identify the following:
(1 point each)
(a) a22
(b) d13
(c) g31
(d) p24
3. (a) Write down the third row of P as a row vector.
(2 points)
(b) Write down the second column of B as a column vector.
(c) Compute DQT .
(2 points)
2
(2 points)
4. Compute the following, or state that the computation cannot be performed.
Remember that matrix multiplication is not commutative!
(a)
D+Q
(b)
PT
(c)
A+B
3
(3 points each)
(d)
BT + A
(e)
P T (A + B T )
(f )
(F + C)C
4
(g)
AF
(h)
FA
(i)
(F B)T
5
(j)
BT F T
Note: It is in general true that (AB)T = B T AT as long as the product AB
is defined. Are your answers in parts (i) and (j) in line with this identity?
(k)
CB
(l)
DG
6