Chapter 5
Precalculus: Functions and Graphs · 379 exercises
Problem 63
Graph the equation on the Interval \([-2,2]\), and describe the behavior of \(y\) as \(x \rightarrow 0^{-}\) and as \(x \rightarrow 0^{+}\) \(y=\sin \frac{1}{x}\)
6 step solution
Problem 63
A ship leaves port at 1: 00 P.M. and sails in the direction \(\mathrm{N} 34^{\circ} \mathrm{W}\) at a rate of \(24 \mathrm{mi} / \mathrm{hr}\). Another ship leaves port at 1: 30 p.M. and sails in the direction \(N 56^{\circ} \mathrm{E}\) at a rate of \(18 \mathrm{mi} / \mathrm{hr}\) (a) Approximately how far apart are the ships at 3: 00 P.M.? (b) What is the bearing, to the nearest degree, from the first ship to the second?
6 step solution
Problem 63
Find the intervals between \(-2 \pi\) and \(2 \pi\) on which the given function is (a) increasing or (b) decreasing. secant
5 step solution
Problem 63
Sketch the graph of the equation. $$y=2^{-x} \cos x$$
5 step solution
Problem 63
Verify the identity by transforming the lefthand side into the right-hand side. $$\sec \theta-\cos \theta=\tan \theta \sin \theta$$
6 step solution
Problem 64
Graph the equation on the Interval \([-2,2]\), and describe the behavior of \(y\) as \(x \rightarrow 0^{-}\) and as \(x \rightarrow 0^{+}\) \(y=|x| \sin \frac{1}{x}\)
4 step solution
Problem 64
Sketch the graph of the equation. $$y=e^{x} \sin x$$
7 step solution
Problem 64
Verify the identity by transforming the lefthand side into the right-hand side. $$\frac{\sin \theta+\cos \theta}{\cos \theta}=1+\tan \theta$$
5 step solution
Problem 65
An airplane flying at a speed of \(360 \mathrm{mi} / \mathrm{hr}\) flies from a point \(A\) in the direction \(137^{\circ}\) for 30 minutes and then flies in the direction \(227^{\circ}\) for 45 minutes. Approximate, to the nearest mile, the distance from the airplane to \(A\).
8 step solution
Problem 65
Graph the equation on the Interval \([-2,2]\), and describe the behavior of \(y\) as \(x \rightarrow 0^{-}\) and as \(x \rightarrow 0^{+}\) \(y=\frac{\sin 2 x}{x}\)
5 step solution
Problem 65
Find the intervals between \(-2 \pi\) and \(2 \pi\) on which the given function is (a) increasing or (b) decreasing. tangent
4 step solution
Problem 65
Sketch the graph of the equation. $$y=|x| \sin x$$
6 step solution
Problem 65
Verify the identity by transforming the lefthand side into the right-hand side. $$(\cot \theta+\csc \theta)(\tan \theta-\sin \theta)=\sec \theta-\cos \theta$$
4 step solution
Problem 66
An airplane flying at a speed of \(400 \mathrm{mi} / \mathrm{hr}\) flies from a point \(A\) in the direction \(153^{\circ}\) for 1 hour and then flies in the direction \(63^{\circ}\) for 1 hour. (a) In what direction does the plane need to fly in order to get back to point \(A ?\) (b) How long will it take to get back to point \(A ?\)
5 step solution
Problem 66
Graph the equation on the Interval \([-2,2]\), and describe the behavior of \(y\) as \(x \rightarrow 0^{-}\) and as \(x \rightarrow 0^{+}\) \(y=\frac{1-\cos 3 x}{x}\)
5 step solution
Problem 66
Find the intervals between \(-2 \pi\) and \(2 \pi\) on which the given function is (a) increasing or (b) decreasing. cotangent
4 step solution
Problem 66
Sketch the graph of the equation. $$y=|x| \cos x$$
5 step solution
Problem 66
Verify the identity by transforming the lefthand side into the right-hand side. $$\cot \theta+\tan \theta=\csc \theta \sec \theta$$
6 step solution
Problem 67
The formula specifles the position of a point \(P\) that is moving harmonically on a vertical axis, where \(t\) is in seconds and \(d\) is in centimeters. Determine the amplitude, period, and frequency, and describe the motion of the point during one complete oscillation (starting at \(t=0\) ). $$d=10 \sin 6 \pi t$$
4 step solution
Problem 67
Graph the equation on the Interval \([-20,20]\), and estimate the hortzontal asymptote. \(y=x^{2} \sin ^{2}\left(\frac{2}{x}\right)\)
5 step solution
Problem 67
Practice sketching the graph of the sine function, taking different units of length on the horizontal and vertical axes. Practice sketching graphs of the cosine and tangent functions in the same manner. Continue this practice until you reach the stage at which, if you were awakened from a sound sleep in the middle of the night and asked to sketch one of these graphs, you could do so in less than thirty seconds.
6 step solution
Problem 67
Graph the function \(f\) in the viewing rectangle \([-2 \pi, 2 \pi, \pi / 2]\) by \([-4,4] .\) Use the graph of \(f\) to predict the graph of \(g .\) Verify your prediction by graphing \(g\) in the same vlewing rectangle. $$f(x)=\tan 0.5 x ; \quad g(x)=\tan \left[0.5\left(x+\frac{\pi}{2}\right)\right]$$
4 step solution
Problem 67
Verify the identity by transforming the lefthand side into the right-hand side. $$\sec ^{2} 3 \theta \csc ^{2} 3 \theta=\sec ^{2} 3 \theta+\csc ^{2} 3 \theta$$
3 step solution
Problem 68
The formula specifles the position of a point \(P\) that is moving harmonically on a vertical axis, where \(t\) is in seconds and \(d\) is in centimeters. Determine the amplitude, period, and frequency, and describe the motion of the point during one complete oscillation (starting at \(t=0\) ). $$d=\frac{1}{3} \cos \frac{\pi}{4} t$$
5 step solution
Problem 68
Graph the equation on the Interval \([-20,20]\), and estimate the hortzontal asymptote. \(y=\frac{1-\cos ^{2}(2 / x)}{\sin (1 / x)}\)
4 step solution
Problem 68
Graph the function \(f\) in the viewing rectangle \([-2 \pi, 2 \pi, \pi / 2]\) by \([-4,4] .\) Use the graph of \(f\) to predict the graph of \(g .\) Verify your prediction by graphing \(g\) in the same vlewing rectangle. $$f(x)=0.5 \csc 0.5 x, g(x)=0.5 \csc 0.5 x-2$$
5 step solution
Problem 68
Verify the identity by transforming the lefthand side into the right-hand side. $$\frac{1+\cos ^{2} 3 \theta}{\sin ^{2} 3 \theta}=2 \csc ^{2} 3 \theta-1$$
5 step solution
Problem 69
The formula specifles the position of a point \(P\) that is moving harmonically on a vertical axis, where \(t\) is in seconds and \(d\) is in centimeters. Determine the amplitude, period, and frequency, and describe the motion of the point during one complete oscillation (starting at \(t=0\) ). $$d=4 \cos \frac{3 \pi}{2} t$$
4 step solution
Problem 69
Graph the function \(f\) in the viewing rectangle \([-2 \pi, 2 \pi, \pi / 2]\) by \([-4,4] .\) Use the graph of \(f\) to predict the graph of \(g .\) Verify your prediction by graphing \(g\) in the same vlewing rectangle. $$f(x)=0.5 \sec 0.5 x, \quad g(x)=0.5 \sec \left[0.5\left(x-\frac{\pi}{2}\right)\right]-1$$
6 step solution
Problem 69
Verify the identity by transforming the lefthand side into the right-hand side. $$\log \csc \theta=-\log \sin \theta$$
6 step solution
Problem 70
The formula specifles the position of a point \(P\) that is moving harmonically on a vertical axis, where \(t\) is in seconds and \(d\) is in centimeters. Determine the amplitude, period, and frequency, and describe the motion of the point during one complete oscillation (starting at \(t=0\) ). $$d=6 \sin \frac{2 \pi}{3} t$$
5 step solution
Problem 70
Use a graph to solve the Inequality on the interval \([-\pi, \pi]\) \(\frac{1}{4} \tan \left(\frac{1}{3} x^{2}\right)<\frac{1}{2} \cos 2 x+\frac{1}{5} x^{2}\)
6 step solution
Problem 70
Graph the function \(f\) in the viewing rectangle \([-2 \pi, 2 \pi, \pi / 2]\) by \([-4,4] .\) Use the graph of \(f\) to predict the graph of \(g .\) Verify your prediction by graphing \(g\) in the same vlewing rectangle. $$f(x)=\tan x-1 ; \quad g(x)=-\tan x+1$$
6 step solution
Problem 70
Verify the identity by transforming the lefthand side into the right-hand side. $$\log \tan \theta=\log \sin \theta-\log \cos \theta$$
5 step solution
Problem 71
A point \(P\) in simple harmonic motion has a period of 3 seconds and an amplitude of 5 centimeters. Express the motion of \(P\) by means of an equation of the form \(d=a \cos \omega t\)
5 step solution
Problem 71
Graph the function \(f\) in the viewing rectangle \([-2 \pi, 2 \pi, \pi / 2]\) by \([-4,4] .\) Use the graph of \(f\) to predict the graph of \(g .\) Verify your prediction by graphing \(g\) in the same vlewing rectangle. $$f(x)=3 \cos 2 x ; \quad g(x)=|3 \cos 2 x|-1$$
6 step solution
Problem 71
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and \(P\) is on the terminal side. $$P(4,-3)$$
8 step solution
Problem 72
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and \(P\) is on the terminal side. $$P(-8,-15)$$
7 step solution
Problem 73
On March \(17,1981,\) in Tucson, Arizona, the temperature in degrees Fahrenheit could be described by the equation $$T(t)=-12 \cos \left(\frac{\pi}{12} t\right)+60$$ while the relative humidity in percent could be expressed by $$H(t)=20 \cos \left(\frac{\pi}{12} t\right)+60$$ where \(t\) is in hours and \(t=0\) corresponds to 6 A.M. (a) Construct a table that lists the temperature and relative humidity every three hours, beginning at midnight. (b) Determine the times when the maximums and minimums occurred for \(T\) and \(H\) (c) Discuss the relationship between the temperature and relative humidity on this day.
4 step solution
Problem 73
Identify the damping factor \(f(x)\) for the damped wave. Sketch graphs of \(y=\pm f(x)\) and the equation on the same coordinate plane for \(-2 \pi \leq x \leq 2 \pi\) $$y=e^{-x^{4}} \sin 4 x$$
3 step solution
Problem 73
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and \(P\) is on the terminal side. $$P(-2,-5)$$
4 step solution
Problem 74
Identify the damping factor \(f(x)\) for the damped wave. Sketch graphs of \(y=\pm f(x)\) and the equation on the same coordinate plane for \(-2 \pi \leq x \leq 2 \pi\) $$y=3^{-x / 3} \cos 2 x$$
5 step solution
Problem 74
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and \(P\) is on the terminal side. $$P(-1,2)$$
8 step solution
Problem 75
Graph the equation, and estimate the values of \(x\) in the specified interval that correspond to the given value of \(y\) $$y=\sin \left(x^{2}\right), \quad[-\pi, \pi] ; \quad y=0.5$$
5 step solution
Problem 75
Graph the function \(f\) on \([-\pi, \pi],\) and estimate the high and low points. $$f(x)=\cos 2 x+2 \sin 4 x-\sin x$$
4 step solution
Problem 75
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and the terminal side of \(\boldsymbol{\theta}\) is in the specified quadrant and satisfles the given condition. II; on the line \(y=-4 x\)
4 step solution
Problem 76
Graph the equation, and estimate the values of \(x\) in the specified interval that correspond to the given value of \(y\) $$y=\tan (\sqrt{x}), \quad[0,25] ; \quad y=5$$
5 step solution
Problem 76
Graph the function \(f\) on \([-\pi, \pi],\) and estimate the high and low points. $$f(x)=\tan \frac{1}{4} x-2 \sin 2 x$$
5 step solution
Problem 76
Find the exact values of the six trigonometric functions of \(\boldsymbol{\theta}\) if \(\boldsymbol{\theta}\) is in standard position and the terminal side of \(\boldsymbol{\theta}\) is in the specified quadrant and satisfles the given condition. IV; on the line \(3 y+5 x=0\)
6 step solution
Problem 77
Graph \(f\) on the Interval \([-2 \pi, 2 \pi],\) and estimate the coordinates of the high and low points. $$f(x)=x \sin x$$
7 step solution