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

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Chapter 3 - Differential Equations and Linear Algebra Solutions | StudyQuestionHub