Chapter 3
Differential Equations and Linear Algebra · 241 exercises
Problem 1
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rr} 6 & 6 \\ -2 & 1 \end{array}\right]$$.
4 step solution
Problem 1
Evaluate the given determinant. $$|-3|$$
2 step solution
Problem 1
Determine all minors and cofactors of the given matrix. $$A=\left[\begin{array}{rr} -9 & 2 \\ 0 & 5 \end{array}\right]$$
5 step solution
Problem 1
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rr} -2 & 5 \\ 5 & -4 \end{array}\right|$$
4 step solution
Problem 1
Determine the number of inversions and the parity of the given permutation. (3,1,4,2).
3 step solution
Problem 2
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rr} -7 & -2 \\ 1 & -5 \end{array}\right]$$.
4 step solution
Problem 2
Evaluate the given determinant. $$\left|\begin{array}{rr}5 & -1 \\\3 & 7\end{array}\right|.$$
3 step solution
Problem 2
Determine all minors and cofactors of the given matrix. $$A=\left[\begin{array}{rr} 1 & -3 \\ 2 & 4 \end{array}\right]$$
2 step solution
Problem 2
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 1 & 2 & 3 \\ 2 & 6 & 4 \\ 3 & -5 & 2 \end{array}\right|$$
2 step solution
Problem 2
Determine the number of inversions and the parity of the given permutation. (2,4,3,1).
4 step solution
Problem 3
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rrr} 2 & 3 & -5 \\ -4 & 0 & 2 \\ 6 & -3 & 3 \end{array}\right]$$.
9 step solution
Problem 3
Evaluate the given determinant. $$\left|\begin{array}{rrr}3 & 5 & 7 \\\\-1 & 2 & 4 \\\6 & 3 & -2\end{array}\right|.$$
4 step solution
Problem 3
Determine all minors and cofactors of the given matrix. $$A=\left[\begin{array}{rrr} 1 & -1 & 2 \\ 3 & -1 & 4 \\ 2 & 1 & 5 \end{array}\right]$$
10 step solution
Problem 3
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 2 & -1 & 4 \\ 3 & 2 & 1 \\ -2 & 1 & 4 \end{array}\right|$$
4 step solution
Problem 3
Determine the number of inversions and the parity of the given permutation. (5,4,3,2,1).
4 step solution
Problem 4
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rrr} -1 & 4 & 1 \\ 0 & 2 & 2 \\ 2 & 2 & -3 \end{array}\right]$$.
7 step solution
Problem 4
Evaluate the given determinant. $$\left|\begin{array}{rrr}5 & 1 & 4 \\\6 & 1 & 3 \\\14 & 2 & 7\end{array}\right|.$$
4 step solution
Problem 4
Determine all minors and cofactors of the given matrix. $$A=\left[\begin{array}{rrr} 2 & 10 & 3 \\ 0 & -1 & 0 \\ 4 & 1 & 5 \end{array}\right]$$
18 step solution
Problem 4
Determine the number of inversions and the parity of the given permutation. (2,4,1,5,3).
3 step solution
Problem 4
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 2 & 1 & 3 \\ -1 & 2 & 6 \\ 4 & 1 & 12 \end{array}\right|$$
3 step solution
Problem 5
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rrrr} 0 & 0 & 0 & -2 \\ 0 & 0 & -5 & 1 \\ 0 & 1 & -4 & 1 \\ -3 & -3 & -3 & -3 \end{array}\right]$$.
4 step solution
Problem 5
Evaluate the given determinant. $$\left|\begin{array}{ccc}2.3 & 1.5 & 7.9 \\\4.2 & 3.3 & 5.1 \\\6.8 & 3.6 & 5.7\end{array}\right|.$$
5 step solution
Problem 5
Determine all minors and cofactors of the given matrix. $$\text { If } A=\left[\begin{array}{rrrr} 1 & 3 & -1 & 2 \\ 3 & 4 & 1 & 2 \\ 7 & 1 & 4 & 6 \\ 5 & 0 & 1 & 2 \end{array}\right]$$ determine the minors \(\vec{M}_{12}, M_{31}, M_{23}, M_{42},\) and the corresponding cofactors.
5 step solution
Problem 5
Determine the number of inversions and the parity of the given permutation. (6,1,4,2,5,3).
2 step solution
Problem 5
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 0 & 1 & -2 \\ -1 & 0 & 3 \\ 2 & -3 & 0 \end{array}\right|$$
4 step solution
Problem 6
Evaluate the determinant of the given matrix \(A\) by using (a) Definition \(3.1 .8,\) (b) elementary row operations to reduce \(A\) to an upper triangular matrix, and (c) the Cofactor Expansion Theorem. $$A=\left[\begin{array}{rrrr} 3 & -1 & -2 & 1 \\ 0 & 0 & 1 & 4 \\ 0 & 2 & 1 & -1 \\ 0 & 0 & 0 & -4 \end{array}\right]$$.
4 step solution
Problem 6
Evaluate the given determinant. $$\left|\begin{array}{lll}a & b & c \\\b & c & a \\\c & a & b\end{array}\right|.$$
6 step solution
Problem 6
If $$ A=\left[\begin{array}{rrrr} -2 & 9 & 0 & -1 \\ 4 & -6 & 8 & 8 \\ 0 & -1 & -3 & 4 \\ 7 & -7 & 3 & 1 \end{array}\right] $$ determine the minors \(M_{41}, M_{22}, M_{23}, M_{43},\) and the corresponding cofactors.
5 step solution
Problem 6
Determine the number of inversions and the parity of the given permutation. (6,5,4,3,2,1).
4 step solution
Problem 6
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 3 & 7 & 1 \\ 5 & 9 & -6 \\ 2 & 1 & 3 \end{array}\right|$$
5 step solution
Problem 7
Suppose that $$A=\left[\begin{array}{lll} a & b & c \\ d & e & f \\ g & h & i \end{array}\right] \text { and } \operatorname{det}(A)=4$$. Compute the determinant of each matrix below. $$\left[\begin{array}{ccc} a-5 d & b-5 e & c-5 f \\ 3 g & 3 h & 3 i \\ -d+3 g & -e+3 h & -f+3 i \end{array}\right]$$.
6 step solution
Problem 7
Evaluate the given determinant. $$\left|\begin{array}{rrrr}3 & 5 & -1 & 2 \\\2 & 1 & 5 & 2 \\\3 & 2 & 5 & 7 \\\1 & -1 & 2 & 1 \end{array}\right|.$$
4 step solution
Problem 7
Use the cofactor expansion theorem to evaluate the given determinant along the specified row or column. \(\left|\begin{array}{cc}-8 & 6 \\ -4 & 9\end{array}\right|,\) column 2
6 step solution
Problem 7
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrr} 1 & -1 & 2 & 4 \\ 3 & 1 & 2 & 4 \\ -1 & 1 & 3 & 2 \\ 2 & 1 & 4 & 2 \end{array}\right|$$
2 step solution
Problem 7
Use Definition 3.1 .8 to derive the general expression for the determinant of \(A\) if $$A=\left[\begin{array}{ll}a_{11} & a_{12} \\\a_{21} & a_{22}\end{array}\right]$$.
2 step solution
Problem 8
Suppose that $$A=\left[\begin{array}{lll} a & b & c \\ d & e & f \\ g & h & i \end{array}\right] \text { and } \operatorname{det}(A)=4$$. Compute the determinant of each matrix below. $$\left[\begin{array}{rrr} g & h & i \\ -4 a & -4 b & -4 c \\ 2 d & 2 e & 2 f \end{array}\right]$$
4 step solution
Problem 8
Evaluate the given determinant. $$\left|\begin{array}{rrrr}7 & 1 & 2 & 3 \\\2 & -2 & 4 & 6 \\\3 & -1 & 5 & 4 \\\18 & 9 & 27 & 54 \end{array}\right|.$$
5 step solution
Problem 8
Use the cofactor expansion theorem to evaluate the given determinant along the specified row or column. \(\left|\begin{array}{rr}1 & -2 \\ 1 & 3\end{array}\right|,\) row 1
3 step solution
Problem 8
Determine whether the given expression is a term in the determinant of order \(5 .\) If it is, determine whether the permutation of the column indices has even or odd parity and hence find whether the term has a plus or a minus sign attached to it. $$a_{11} a_{23} a_{34} a_{43} a_{52}$$.
3 step solution
Problem 8
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrrr} 2 & 32 & 1 & 4 \\ 26 & 104 & 26 & -13 \\ 2 & 56 & 2 & 7 \\ 1 & 40 & 1 & 5 \end{array}\right|$$
2 step solution
Problem 9
Suppose that $$A=\left[\begin{array}{lll} a & b & c \\ d & e & f \\ g & h & i \end{array}\right] \text { and } \operatorname{det}(A)=4$$. Compute the determinant of each matrix below. $$3 \cdot\left[\begin{array}{ccc} a-d & b-e & c-f \\ 2 g & 2 h & 2 i \\ -d & -e & -f \end{array}\right]$$.
6 step solution
Problem 9
Find \(\operatorname{det}(A) .\) If \(A\) is invertible, use the adjoint method to find \(A^{-1}\). $$A=\left[\begin{array}{ll}3 & 5 \\\2 & 7\end{array}\right]$$
2 step solution
Problem 9
Use the cofactor expansion theorem to evaluate the given determinant along the specified row or column. \(\left|\begin{array}{rrr}-1 & 2 & 3 \\ 1 & 4 & -2 \\ 3 & 1 & 4\end{array}\right|,\) column 3
3 step solution
Problem 9
Determine whether the given expression is a term in the determinant of order \(5 .\) If it is, determine whether the permutation of the column indices has even or odd parity and hence find whether the term has a plus or a minus sign attached to it. $$a_{11} a_{25} a_{33} a_{42} a_{54}$$.
3 step solution
Problem 9
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{rrrr} 0 & 1 & -1 & 1 \\ -1 & 0 & 1 & 1 \\ 1 & -1 & 0 & 1 \\ -1 & -1 & -1 & 0 \end{array}\right|$$
5 step solution
Problem 10
Suppose that $$A=\left[\begin{array}{lll} a & b & c \\ d & e & f \\ g & h & i \end{array}\right] \text { and } \operatorname{det}(A)=4$$. Compute the determinant of each matrix below. $$\left[\begin{array}{ccc} 3 b & 3 e & 3 h \\ c-2 a & f-2 d & i-2 g \\ -a & -d & -g \end{array}\right]$$.
8 step solution
Problem 10
Find \(\operatorname{det}(A) .\) If \(A\) is invertible, use the adjoint method to find \(A^{-1}\). $$A=\left[\begin{array}{lll}1 & 2 & 3 \\\2 & 3 & 1 \\\3 & 1 & 2\end{array}\right].$$
5 step solution
Problem 10
Use the cofactor expansion theorem to evaluate the given determinant along the specified row or column. \(\left|\begin{array}{rrr}2 & 1 & -4 \\ 7 & 1 & 3 \\ 1 & 5 & -2\end{array}\right|,\) row 2
5 step solution
Problem 10
Determine whether the given expression is a term in the determinant of order \(5 .\) If it is, determine whether the permutation of the column indices has even or odd parity and hence find whether the term has a plus or a minus sign attached to it. $$a_{11} a_{32} a_{24} a_{43} a_{55}$$.
3 step solution
Problem 10
Evaluate the determinant of the given matrix by first using elementary row operations to reduce it to upper triangular form. $$\left|\begin{array}{llll} 2 & 1 & 3 & 5 \\ 3 & 0 & 1 & 2 \\ 4 & 1 & 4 & 3 \\ 5 & 2 & 5 & 3 \end{array}\right|$$
2 step solution