Homework 2
MAT 281E
1. (30 pts.) The matrices are given,
A =
−1 −2 −3
0 3 −1
0 4 2
, B =
−5 1 2
−2 4 8
−4 −5 −6
a) Evaluate det(A) and det(B) by cofactor expansion along the first column of the
matrices.
b) Evaluate det(A) and det(B) using row reduction.
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Name:
Number: Homework 2
MAT 281E
October 15, 2019
2. (20 pts.) Solve the lineer system by using Cramer’s rule
x − 2y + z = 7
3x − y + z = −2
2x + 3y − 2z = −10
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Name:
Number: Homework 2
MAT 281E
October 15, 2019
3. (30 pts.) Evaluate the given expressions with
u = (3, −1, 2) , v = (2, −3, 5) and w = (1, 6, −2)
a) ||u + 2v||
b) ||3v|| − ||2w||
c) ||2u − v + 3w||
4
Name:
Number: Homework 2
MAT 281E
October 15, 2019
4. (20 pts.) Find u · v , u · u and v · v
a) u = (2, 3, 1), v = (3, 3, 0)
b) u = (−2, −1, 0, −3, 1) , v = (2, 1, 3, 2, 4)
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