Chapter 10

Algebra and Trigonometry · 305 exercises

Problem 50

Find the unit vector in the same direction as \(\mathbf{V}\). \(\mathbf{v}=-3 \mathbf{j}\)

3 step solution

Problem 50

Write each expression in rectangular form \(x+\) yi and in exponential form \(r e^{i \theta} .\) $$ \left[\frac{1}{2}\left(\cos \frac{2 \pi}{5}+i \sin \frac{2 \pi}{5}\right)\right]^{5} $$

5 step solution

Problem 50

Identify and graph each polar equation. $$ r=2+4 \cos \theta $$

5 step solution

Problem 51

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ \left(-5,-\frac{\pi}{6}\right) $$

6 step solution

Problem 51

Find the unit vector in the same direction as \(\mathbf{V}\). \(\mathbf{v}=3 \mathbf{i}-4 \mathbf{j}\)

3 step solution

Problem 52

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Find the average rate of change of \(f(x)=x^{3}-5 x^{2}+27\) from -3 to 2 .

4 step solution

Problem 52

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ \left(-6,-\frac{\pi}{4}\right) $$

5 step solution

Problem 52

Find the unit vector in the same direction as \(\mathbf{V}\). \(\mathbf{v}=-5 \mathbf{i}+12 \mathbf{j}\)

5 step solution

Problem 52

Write each expression in rectangular form \(x+\) yi and in exponential form \(r e^{i \theta} .\) $$ \left[\sqrt{3} e^{i \frac{5 \pi}{18}}\right]^{6} $$

5 step solution

Problem 52

Identify and graph each polar equation. $$ r=2 \sin (3 \theta) $$

5 step solution

Problem 53

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Find the exact value of \(5 \cos 60^{\circ}+2 \tan \frac{\pi}{4} .\) Do not use a calculator.

4 step solution

Problem 53

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ (-2,-\pi) $$

3 step solution

Problem 53

Find the unit vector in the same direction as \(\mathbf{V}\). \(\mathbf{v}=\mathbf{i}-\mathbf{j}\)

2 step solution

Problem 53

In Problems \(45-56,\) write each expression in rectangular form \(x+y i\) and in exponential form re". 53\. \((1-i)^{5}\)

3 step solution

Problem 53

Identify and graph each polar equation. $$ r=4 \sin (5 \theta) $$

4 step solution

Problem 54

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ \left(-3,-\frac{\pi}{2}\right) $$

4 step solution

Problem 54

Write each expression in rectangular form \(x+\) yi and in exponential form \(r e^{i \theta} .\) $$ (\sqrt{3}-i)^{6} $$

4 step solution

Problem 54

Identify and graph each polar equation. $$ r=3 \cos (4 \theta) $$

6 step solution

Problem 55

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Volume of a Box An open-top box is made from a sheet of metal by cutting squares from each corner and folding up the sides. The sheet has a length of 19 inches and a width of 13 inches. If \(x\) is the length of one side of each square to be cut out, write a function, \(V(x),\) for the volume of the box in terms of \(x\).

4 step solution

Problem 55

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ \left(7.5, \frac{11 \pi}{18}\right) $$

5 step solution

Problem 55

If \(\|\mathbf{v}\|=4,\) what is the magnitude of \(\frac{1}{2} \mathbf{v}+3 \mathbf{v} ?\)

4 step solution

Problem 55

Write each expression in rectangular form \(x+\) yi and in exponential form \(r e^{i \theta} .\) $$ (\sqrt{2}-i)^{6} $$

3 step solution

Problem 55

Identify and graph each polar equation. $$ r^{2}=9 \cos (2 \theta) $$

5 step solution

Problem 56

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Solve: \(7^{x-1}=3 \cdot 2^{x+4}\)

4 step solution

Problem 56

Polar coordinates of a point are given. Find the rectangular coordinates of each point. $$ \left(-3.1, \frac{91 \pi}{90}\right) $$

4 step solution

Problem 56

Write each expression in rectangular form \(x+\) yi and in exponential form \(r e^{i \theta} .\) $$ (1-\sqrt{5} i)^{8} $$

8 step solution

Problem 56

Identify and graph each polar equation. $$ r^{2}=\sin (2 \theta) $$

5 step solution

Problem 57

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. What is the function that is graphed after the graph of \(y=\sqrt[3]{x}\) is shifted left 4 units and up 9 units?

3 step solution

Problem 57

Find a vector \(\mathbf{v}\) whose magnitude is 4 and whose component in the \(\mathbf{i}\) direction is twice the component in the \(\mathbf{j}\) direction.

4 step solution

Problem 58

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Find all asymptotes of the graph of \(f(x)=\frac{2 x^{2}-5}{x^{2}-2 x-15}\)

4 step solution

Problem 58

Find a vector \(\mathbf{v}\) whose magnitude is 3 and whose component in the \(\mathbf{i}\) direction is equal to the component in the \(\mathbf{j}\) direction.

8 step solution

Problem 58

Find all the complex roots. Write your answers in exponential form. The complex fourth roots of \(\sqrt{3}-i\)

4 step solution

Problem 59

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Find the exact value of \(\cos 80^{\circ} \cos 70^{\circ}-\sin 80^{\circ} \sin 70^{\circ}\).

4 step solution

Problem 59

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (3,0) $$

4 step solution

Problem 59

If \(\mathbf{v}=2 \mathbf{i}-\mathbf{j}\) and \(\mathbf{w}=x \mathbf{i}+3 \mathbf{j},\) find all numbers \(x\) for which \(\|\mathbf{v}+\mathbf{w}\|=5\)

4 step solution

Problem 59

Find all the complex roots. Write your answers in exponential form. The complex fourth roots of \(4-4 \sqrt{3} i\)

3 step solution

Problem 59

Identify and graph each polar equation. $$ r=1-\cos \theta $$

5 step solution

Problem 60

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Find the vertex and determine if the graph of \(f(x)=\frac{2}{3} x^{2}-12 x+10\) is concave up or concave down.

5 step solution

Problem 60

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (0,2) $$

4 step solution

Problem 60

If \(P=(-3,1)\) and \(Q=(x, 4),\) find all numbers \(x\) so that the vector represented by \(\overline{P Q}\) has length 5 .

5 step solution

Problem 61

Based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. If \(f(x)=\frac{1}{\left(x^{2}+9\right)^{3 / 2}}\) and \(g(x)=3 \tan x,\) show that\((f \circ g)(x)=\frac{1}{27\left|\sec ^{3} x\right|}\)

5 step solution

Problem 61

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (-1,0) $$

5 step solution

Problem 61

Write the vector \(\mathbf{v}\) in the form \(\mathbf{ai}+ \mathbf{bj}\), given its magnitude \(\|\mathbf{v}\|\) and the angle \(\alpha\) it makes with the positive \(x\) -axis. \(|\mathbf{v}|=5, \quad \alpha=60^{\circ}\)

4 step solution

Problem 61

Identify and graph each polar equation. $$ r=1-3 \cos \theta $$

5 step solution

Problem 62

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (0,-2) $$

4 step solution

Problem 62

Write the vector \(\mathbf{v}\) in the form \(\mathbf{ai}+ \mathbf{bj}\), given its magnitude \(\|\mathbf{v}\|\) and the angle \(\alpha\) it makes with the positive \(x\) -axis. \(\mid \mathbf{v} \|=8, \quad \alpha=45^{\circ}\)

4 step solution

Problem 62

Find all the complex roots. Write your answers in exponential form. The complex cube roots of -8

5 step solution

Problem 62

Identify and graph each polar equation. $$ r=4 \cos (3 \theta) $$

5 step solution

Problem 63

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (1,-1) $$

4 step solution

Problem 64

The rectangular coordinates of a point are given. Find polar coordinates for each point. $$ (-3,3) $$

4 step solution

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