Chapter 7

Algebra and Trigonometry · 570 exercises

Problem 1

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \mathbf{w}=\mathbf{i}+3 \mathbf{j} $$

2 step solution

Problem 1

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=4 i $$

3 step solution

Problem 2

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=3 \mathbf{i}+3 \mathbf{j}, \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j} $$

3 step solution

Problem 2

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=3 i $$

3 step solution

Problem 3

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=5 \mathbf{i}-4 \mathbf{j}, \quad \mathbf{w}=-2 \mathbf{i}-\mathbf{j} $$

2 step solution

Problem 3

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=3 $$

3 step solution

Problem 4

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=7 \mathbf{i}-2 \mathbf{j}, \quad \mathbf{w}=-3 \mathbf{i}-\mathbf{j} $$

3 step solution

Problem 4

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=4 $$

3 step solution

Problem 5

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=-6 \mathbf{i}-5 \mathbf{j}, \quad \mathbf{w}=-10 \mathbf{i}-8 \mathbf{j} $$

3 step solution

Problem 5

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$\mathbf{v}=3 \mathbf{i}+\mathbf{j}$$

3 step solution

Problem 5

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=3+2 i $$

3 step solution

Problem 6

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=-8 \mathbf{i}-3 \mathbf{j}, \quad \mathbf{w}=-10 \mathbf{i}-5 \mathbf{j} $$

2 step solution

Problem 6

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$\mathbf{v}=2 \mathbf{i}+3 \mathbf{j}$$

3 step solution

Problem 6

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=2+5 i $$

3 step solution

Problem 7

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole.$$ r=\sin \theta$$

3 step solution

Problem 7

Use the given vectors to find \(\mathbf{v} \cdot \mathbf{w}\) and \(\mathbf{v} \cdot \mathbf{v}\). $$ \mathbf{v}=5 \mathbf{i}, \quad \mathbf{w}=\mathbf{j} $$

3 step solution

Problem 7

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$\mathbf{v}=\mathbf{i}-\mathbf{j}$$

3 step solution

Problem 7

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=3-i $$

3 step solution

Problem 8

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole. $$ r=\cos \theta $$

3 step solution

Problem 8

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$\mathbf{v}=-\mathbf{i}-\mathbf{j}$$

2 step solution

Problem 8

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=4-i $$

2 step solution

Problem 9

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole. $$ r=4+3 \cos \theta $$

3 step solution

Problem 9

Let $$\mathbf{u}=2 \mathbf{i}-\mathbf{j}, \quad \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \text { and } \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j}$$ Find each specified scalar. $$ \mathbf{u} \cdot(\mathbf{v}+\mathbf{w}) $$

3 step solution

Problem 9

Solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$a=5, b=7, C=42^{\circ}$$

4 step solution

Problem 9

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=-3+4 i $$

3 step solution

Problem 9

In Exercises 9–16, solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$ A=44^{\circ}, B=25^{\circ}, a=12 $$

3 step solution

Problem 10

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole. $$ r=2 \cos 2 \theta $$

3 step solution

Problem 10

Let $$\mathbf{u}=2 \mathbf{i}-\mathbf{j}, \quad \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \text { and } \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j}$$ Find each specified scalar. $$ \mathbf{v} \cdot(\mathbf{u}+\mathbf{w}) $$

3 step solution

Problem 10

Solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$a=10, b=3, C=15^{\circ}$$

4 step solution

Problem 10

In Exercises \(1-10,\) plot each complex number and find its absolute value. $$ z=-3-4 i $$

3 step solution

Problem 10

In Exercises 9–16, solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$ A=56^{\circ}, C=24^{\circ}, a=22 $$

3 step solution

Problem 11

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole. $$ r^{2}=16 \cos 2 \theta $$

3 step solution

Problem 11

Let $$\mathbf{u}=2 \mathbf{i}-\mathbf{j}, \quad \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \text { and } \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j}$$ Find each specified scalar. $$ \mathbf{u} \cdot \mathbf{v}+\mathbf{u} \cdot \mathbf{w} $$

3 step solution

Problem 11

Solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$b=5, c=3, A=102^{\circ}$$

3 step solution

Problem 11

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$\mathbf{v}=-4 \mathbf{i}$$

3 step solution

Problem 11

In Exercises \(11-26,\) plot each complex number. Then write the complex number in polar form. You may express the argument in degrees or radians. $$ 2+2 i $$

4 step solution

Problem 11

Use a polar coordinate system like the one shown for Exercises 1–10 to plot each point with the given polar coordinates. $$ \left(2,45^{\circ}\right) $$

4 step solution

Problem 11

In Exercises 9–16, solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$ B=85^{\circ}, C=15^{\circ}, b=40 $$

4 step solution

Problem 12

Test for symmetry with respect to a. the polar axis. b. the line \(\theta=\frac{\pi}{2}\) c. the pole. $$ r^{2}=16 \sin 2 \theta $$

3 step solution

Problem 12

Let $$\mathbf{u}=2 \mathbf{i}-\mathbf{j}, \quad \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \text { and } \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j}$$ Find each specified scalar. $$ \mathbf{v} \cdot \mathbf{u}+\mathbf{v} \cdot \mathbf{w} $$

4 step solution

Problem 12

Solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$b=4, c=1, A=100^{\circ}$$

3 step solution

Problem 12

In Exercises 5–12, sketch each vector as a position vector and find its magnitude. $$v=-5 j$$

2 step solution

Problem 12

In Exercises \(11-26,\) plot each complex number. Then write the complex number in polar form. You may express the argument in degrees or radians. $$ 1+i \sqrt{3} $$

3 step solution

Problem 12

In Exercises 9–16, solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$ A=85^{\circ}, B=35^{\circ}, c=30 $$

3 step solution

Problem 12

Use a polar coordinate system like the one shown for Exercises 1–10 to plot each point with the given polar coordinates. $$ \left(1,45^{\circ}\right) $$

3 step solution

Problem 13

Test for symmetry and then graph each polar equation. $$r=2 \cos \theta$$

2 step solution

Problem 13

Let $$\mathbf{u}=2 \mathbf{i}-\mathbf{j}, \quad \mathbf{v}=3 \mathbf{i}+\mathbf{j}, \quad \text { and } \quad \mathbf{w}=\mathbf{i}+4 \mathbf{j}$$ Find each specified scalar. $$ (4 \mathbf{u}) \cdot \mathbf{v} $$

3 step solution

Problem 13

Solve each triangle. Round lengths to the nearest tenth and angle measures to the nearest degree. $$a=6, c=5, B=50^{\circ}$$

3 step solution

Problem 13

In Exercises \(13-20\), let v be the vector from initial point \(P_{1}\) to terminal point \(P_{2} .\) Write \(\mathbf{v}\) in terms of \(\mathbf{i}\) and \(\mathbf{j}\) $$P_{1}=(-4,-4), P_{2}=(6,2)$$

3 step solution

Problem 13

In Exercises \(11-26,\) plot each complex number. Then write the complex number in polar form. You may express the argument in degrees or radians. $$ -1-i $$

5 step solution

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Chapter 7 - Algebra and Trigonometry Solutions | StudyQuestionHub