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