Chapter 10

Precalculus: Mathematics for Calculus · 524 exercises

Problem 14

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{rrr} 1 & 3 & -3 \\ 0 & 1 & 5 \end{array}\right]$$

3 step solution

Problem 14

Use the elimination method to find all solutions of the system of equations. $$\left\\{\begin{array}{c} x^{2}-y^{2}=1 \\ 2 x^{2}-y^{2}=x+3 \end{array}\right.$$

6 step solution

Problem 14

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{rr}-7 & 4 \\\8 & -5\end{array}\right]$$

4 step solution

Problem 14

Find the determinant of the matrix, if it exists. $$\left[\begin{array}{rr} 2.2 & -1.4 \\ 0.5 & 1.0 \end{array}\right]$$

5 step solution

Problem 14

Perform the matrix operation, or if it is impossible, explain why. $$\left[\begin{array}{rr} 1 & 2 \\ -1 & 4 \end{array}\right]\left[\begin{array}{rrr} 1 & -2 & 3 \\ 2 & 2 & -1 \end{array}\right]$$

4 step solution

Problem 14

Two equations and their graphs are given. Find the intersection point(s) of the graphs by solving the system. (Graph cannot copy) $$\left\\{\begin{aligned} x+y &=2 \\ 2 x+y &=5 \end{aligned}\right.$$

6 step solution

Problem 14

Perform an operation on the given system that eliminates the indicated variable. Write the new equivalent system. \(\left\\{\begin{array}{rr}-5 x+2 y-3 z= & 3 \\ 10 x-3 y+z= & -20 \\ -x+3 y+z= & 8\end{array}\right.\) Eliminate the \(x\)-term from the second equation.

5 step solution

Problem 15

Find the partial fraction decomposition of the rational function. $$\frac{5}{(x-1)(x+4)}$$

5 step solution

Problem 15

Graph the inequality. $$y>x-3$$

4 step solution

Problem 15

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{llll} 1 & 2 & 8 & 0 \\ 0 & 1 & 3 & 2 \\ 0 & 0 & 0 & 0 \end{array}\right]$$

5 step solution

Problem 15

Two equations and their graphs are given. Find the intersection point(s) of the graphs by solving the system. $$\left\\{\begin{array}{l} x^{2}+y=8 \\ x-2 y=-6 \end{array}\right.$$ (GRAPH CANNOT COPY)

8 step solution

Problem 15

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{rr}6 & -3 \\\\-8 & 4\end{array}\right]$$

2 step solution

Problem 15

Evaluate the minor and cofactor using the matrix \(A\). $$A=\left[\begin{array}{rrr} 1 & 0 & \frac{1}{2} \\ -3 & 5 & 2 \\ 0 & 0 & 4 \end{array}\right]$$$$M_{11}, A_{11}$$

4 step solution

Problem 15

Graph each linear system, either by hand or using a graphing device. Use the graph to determine whether the system has one solution, no solution, or infinitely many solutions. If there is exactly one solution, use the graph to find it. $$\left\\{\begin{array}{r} x-y=4 \\ 2 x+y=2 \end{array}\right.$$

4 step solution

Problem 15

Perform the matrix operation, or if it is impossible, explain why. $$\left[\begin{array}{rr} 2 & -3 \\ 0 & 1 \\ 1 & 2 \end{array}\right]\left[\begin{array}{l} 5 \\ 1 \end{array}\right]$$

3 step solution

Problem 15

Perform an operation on the given system that eliminates the indicated variable. Write the new equivalent system. \(\left\\{\begin{array}{l}2 x+y-3 z=5 \\ 2 x+3 y+z=13 \\ 6 x-5 y-z=7\end{array}\right.\) Eliminate the \(x\)-term from the third equation.

4 step solution

Problem 16

Find the partial fraction decomposition of the rational function. $$\frac{x+6}{x(x+3)}$$

7 step solution

Problem 16

Graph the inequality. $$y \leq 1-x$$

4 step solution

Problem 16

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{rrrr} 1 & 0 & -7 & 0 \\ 0 & 1 & 3 & 0 \\ 0 & 0 & 0 & 1 \end{array}\right]$$

4 step solution

Problem 16

Two equations and their graphs are given. Find the intersection point(s) of the graphs by solving the system. $$\left\\{\begin{array}{l} x-y^{2}=-4 \\ x-y=2 \end{array}\right.$$ (GRAPH CANNOT COPY)

7 step solution

Problem 16

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{ll}\frac{1}{2} & \frac{1}{3} \\\5 & 4\end{array}\right]$$

6 step solution

Problem 16

Evaluate the minor and cofactor using the matrix \(A\). $$A=\left[\begin{array}{rrr} 1 & 0 & \frac{1}{2} \\ -3 & 5 & 2 \\ 0 & 0 & 4 \end{array}\right]$$ $$M_{33}, A_{33}$$

5 step solution

Problem 16

Graph each linear system, either by hand or using a graphing device. Use the graph to determine whether the system has one solution, no solution, or infinitely many solutions. If there is exactly one solution, use the graph to find it. $$\left\\{\begin{array}{l} 2 x-y=4 \\ 3 x+y=6 \end{array}\right.$$

5 step solution

Problem 16

Perform an operation on the given system that eliminates the indicated variable. Write the new equivalent system. \(\left\\{\begin{aligned} x-3 y+2 z &=-1 \\ y+z &=-1 \\ 2 y-z &=1 \end{aligned}\right.\) Eliminate the \(y\) -term from the third equation.

7 step solution

Problem 17

Find the partial fraction decomposition of the rational function. $$\frac{12}{x^{2}-9}$$

6 step solution

Problem 17

Graph the inequality. $$2 x-y \geq-4$$

4 step solution

Problem 17

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{llll} 1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 \\ 0 & 1 & 5 & 1 \end{array}\right]$$

5 step solution

Problem 17

Two equations and their graphs are given. Find the intersection point(s) of the graphs by solving the system. $$\left\\{\begin{aligned} x^{2}+y &=0 \\ x^{3}-2 x-y &=0 \end{aligned}\right.$$ (GRAPH CANNOT COPY)

6 step solution

Problem 17

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{rr}0.4 & -1.2 \\\0.3 & 0.6\end{array}\right]$$

6 step solution

Problem 17

Evaluate the minor and cofactor using the matrix \(A\). $$A=\left[\begin{array}{rrr} 1 & 0 & \frac{1}{2} \\ -3 & 5 & 2 \\ 0 & 0 & 4 \end{array}\right]$$ $$M_{12}, A_{12}$$

3 step solution

Problem 17

Solve the matrix equation for the unknown matrix \(X\), or explain why no solution exists. $$\begin{array}{c}A=\left[\begin{array}{ll}4 & 6 \\\1 & 3\end{array}\right] & B=\left[\begin{array}{ll}2 & 5 \\\3 & 7\end{array}\right] \\\C=\left[\begin{array}{ll}2 & 3 \\\1 & 0 \\\0 & 2\end{array}\right] & D=\left[\begin{array}{lr}10 & 20 \\\30 & 20 \\\10 & 0\end{array}\right]\end{array}$$ $$2 X+A=B$$

5 step solution

Problem 17

Graph each linear system, either by hand or using a graphing device. Use the graph to determine whether the system has one solution, no solution, or infinitely many solutions. If there is exactly one solution, use the graph to find it. $$\left\\{\begin{array}{l} 2 x-3 y=12 \\ -x+\frac{3}{2} y=4 \end{array}\right.$$

3 step solution

Problem 17

Find the complete solution of the linear system, or show that it is inconsistent. \(\left\\{\begin{array}{rr}x-y-z= & 4 \\ 2 y+z= & -1 \\ -x+y-2 z= & 5\end{array}\right.\)

5 step solution

Problem 18

Find the partial fraction decomposition of the rational function. $$\frac{x-12}{x^{2}-4 x}$$

7 step solution

Problem 18

Graph the inequality. $$3 x-y-9<0$$

5 step solution

Problem 18

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{llll} 1 & 0 & 0 & 1 \\ 0 & 1 & 0 & 2 \\ 0 & 0 & 1 & 3 \end{array}\right]$$

5 step solution

Problem 18

Two equations and their graphs are given. Find the intersection point(s) of the graphs by solving the system. $$\left\\{\begin{aligned} x^{2}+y^{2} &=4 x \\ x &=y^{2} \end{aligned}\right.$$ (GRAPH CANNOT COPY

8 step solution

Problem 18

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{lll}4 & 2 & 3 \\\3 & 3 & 2 \\\1 & 0 & 1\end{array}\right]$$

4 step solution

Problem 18

Evaluate the minor and cofactor using the matrix \(A\). $$A=\left[\begin{array}{rrr} 1 & 0 & \frac{1}{2} \\ -3 & 5 & 2 \\ 0 & 0 & 4 \end{array}\right]$$ $$M_{13}, A_{13}$$

3 step solution

Problem 18

Solve the matrix equation for the unknown matrix \(X\), or explain why no solution exists. $$\begin{array}{c}A=\left[\begin{array}{ll}4 & 6 \\\1 & 3\end{array}\right] & B=\left[\begin{array}{ll}2 & 5 \\\3 & 7\end{array}\right] \\\C=\left[\begin{array}{ll}2 & 3 \\\1 & 0 \\\0 & 2\end{array}\right] & D=\left[\begin{array}{lr}10 & 20 \\\30 & 20 \\\10 & 0\end{array}\right]\end{array}$$ $$3 X-B=C$$

4 step solution

Problem 18

$$\left\\{\begin{aligned} 2 x+6 y &=0 \\ -3 x-9 y &=18 \end{aligned}\right.$$

3 step solution

Problem 18

Find the complete solution of the linear system, or show that it is inconsistent. \(\left\\{\begin{aligned} x-y+z &=0 \\ y+2 z &=-2 \\ x+y-z &=2 \end{aligned}\right.\)

5 step solution

Problem 19

Find the partial fraction decomposition of the rational function. $$\frac{4}{x^{2}-4}$$

6 step solution

Problem 19

Graph the inequality. $$-x^{2}+y \geq 5$$

5 step solution

Problem 19

A matrix is given. (a) Determine whether the matrix is in row-echelon form. (b) Determine whether the matrix is in reduced row-echelon form. (c) Write the system of equations for which the given matrix is the augmented matrix. $$\left[\begin{array}{rrrrr} 1 & 3 & 0 & -1 & 0 \\ 0 & 0 & 1 & 2 & 0 \\ 0 & 0 & 0 & 0 & 1 \\ 0 & 0 & 0 & 0 & 0 \end{array}\right]$$

3 step solution

Problem 19

Find all solutions of the system of equations. $$\left\\{\begin{array}{l} y+x^{2}=4 x \\ y+4 x=16 \end{array}\right.$$

4 step solution

Problem 19

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists. $$\left[\begin{array}{rrr}2 & 4 & 1 \\\\-1 & 1 & -1 \\\1 & 4 & 0\end{array}\right]$$

4 step solution

Problem 19

Evaluate the minor and cofactor using the matrix \(A\). $$A=\left[\begin{array}{rrr} 1 & 0 & \frac{1}{2} \\ -3 & 5 & 2 \\ 0 & 0 & 4 \end{array}\right]$$ $$M_{23}, A_{23}$$

4 step solution

Problem 19

Solve the matrix equation for the unknown matrix \(X\), or explain why no solution exists. $$\begin{array}{c}A=\left[\begin{array}{ll}4 & 6 \\\1 & 3\end{array}\right] & B=\left[\begin{array}{ll}2 & 5 \\\3 & 7\end{array}\right] \\\C=\left[\begin{array}{ll}2 & 3 \\\1 & 0 \\\0 & 2\end{array}\right] & D=\left[\begin{array}{lr}10 & 20 \\\30 & 20 \\\10 & 0\end{array}\right]\end{array}$$ $$2(B-X)=D$$

6 step solution

Problem 19

Graph each linear system, either by hand or using a graphing device. Use the graph to determine whether the system has one solution, no solution, or infinitely many solutions. If there is exactly one solution, use the graph to find it. $$\left\\{\begin{aligned} -x+\frac{1}{2} y &=-5 \\ 2 x-y &=10 \end{aligned}\right.$$

3 step solution

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