Chapter 5

Precalculus: Functions and Graphs · 379 exercises

Problem 18

Find the exact value. (a) \(\csc (3 \pi / 4)\) (b) \(\csc (-2 \pi / 3)\)

7 step solution

Problem 18

Find the exact values of the trigonometric functions for the acute angle \(\theta\). $$\cos \theta=\frac{8}{17}$$

6 step solution

Problem 18

Exer. \(17-20\) : Express \(\theta\) in terms of degrees, minutes, and seconds, to the nearest second. $$\theta=1.5$$

5 step solution

Problem 19

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$\beta, b ; a$$

3 step solution

Problem 19

Use a formula for negatives to find the exact value. $$\text { (a) } \cot \left(-\frac{3 \pi}{4}\right) \quad \text { (b) } \sec \left(-180^{\circ}\right) \quad \text { (c) } \csc \left(-\frac{3 \pi}{2}\right)$$

4 step solution

Problem 19

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=\sin \left(\frac{1}{2} x-\frac{\pi}{3}\right)\)

4 step solution

Problem 19

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot \left(x-\frac{\pi}{2}\right)$$

4 step solution

Problem 19

Approximate to three decimal places. (a) \(\sin 73^{\circ} 20^{\prime}\) (b) \(\cos 0.68\)

4 step solution

Problem 19

Find the exact values of the trigonometric functions for the acute angle \(\theta\). $$\tan \theta=\frac{5}{12}$$

4 step solution

Problem 19

Exer. \(17-20\) : Express \(\theta\) in terms of degrees, minutes, and seconds, to the nearest second. $$\theta=5$$

6 step solution

Problem 20

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$\alpha, b ; a$$

3 step solution

Problem 20

Use a formula for negatives to find the exact value. $$\text { (a) } \cot \left(-225^{\circ}\right) \quad \text { (b) } \sec \left(-\frac{\pi}{4}\right) \quad \text { (c) } \csc \left(-45^{\circ}\right)$$

10 step solution

Problem 20

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=\sin \left(\frac{1}{2} x+\frac{\pi}{4}\right)\)

5 step solution

Problem 20

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot \left(x+\frac{\pi}{4}\right)$$

5 step solution

Problem 20

Find the exact values of the trigonometric functions for the acute angle \(\theta\). $$\cot \theta=\frac{7}{24}$$

5 step solution

Problem 21

Verify the identity by transforming the left hand side into the right-hand side. $$\sin (-x) \sec (-x)=-\tan x$$

4 step solution

Problem 21

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$\alpha, a ; \quad c$$

4 step solution

Problem 21

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=6 \sin \pi x\)

5 step solution

Problem 21

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot 2 x$$

5 step solution

Problem 21

Approximate to three decimal places. (a) \(\tan 21^{\circ} 10^{\prime} \) b) \(\cot 1.13\)

5 step solution

Problem 21

Exer. \(21-24:\) Express the angle as a decimal, to the nearest ten-thousandth of a degree. $$37^{\circ} 41^{\prime}$$

4 step solution

Problem 21

Find the exact values of the trigonometric functions for the acute angle \(\theta\). $$\sec \theta=\frac{6}{5}$$

6 step solution

Problem 22

Verify the identity by transforming the left hand side into the right-hand side. $$\csc (-x) \cos (-x)=-\cot x$$

5 step solution

Problem 22

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$\boldsymbol{\beta}, \boldsymbol{a} ; \boldsymbol{c}$$

4 step solution

Problem 22

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=3 \cos \frac{\pi}{2} x\)

4 step solution

Problem 22

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot \frac{1}{2} x$$

4 step solution

Problem 22

Approximate to three decimal places. (a) cot \(9^{\circ} 10^{\prime}\) b) \(\tan 0.75\)

3 step solution

Problem 22

Exer. \(21-24\) : Express the angle as a decimal, to the nearest ten-thousandth of a degree. $$83^{\circ} 17^{\prime}$$

5 step solution

Problem 22

Find the exact values of the trigonometric functions for the acute angle \(\theta\). $$\csc \theta=4$$

7 step solution

Problem 23

Verify the identity by transforming the left hand side into the right-hand side. $$\frac{\cot (-x)}{\csc (-x)}=\cos x$$

6 step solution

Problem 23

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$a, c ; \quad b$$

3 step solution

Problem 23

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=2 \cos \frac{\pi}{2} x\)

4 step solution

Problem 23

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot \frac{1}{3} x$$

4 step solution

Problem 23

Exer. \(21-24\) : Express the angle as a decimal, to the nearest ten-thousandth of a degree. $$115^{\circ} 26^{\prime} 27^{\prime \prime}$$

5 step solution

Problem 23

A forester, 200 feet from the base of a redwood tree, observes that the angle between the ground and the top of the tree is \(60^{\circ} .\) Estimate the height of the tree.

5 step solution

Problem 24

Verify the identity by transforming the left hand side into the right-hand side. $$\frac{\sec (-x)}{\tan (-x)}=-\csc x$$

5 step solution

Problem 24

Given the indicated parts of triangle \(A B C\) with \(\gamma=90^{\circ},\) express the third part in terms of the first two. $$a, b ; \quad c$$

2 step solution

Problem 24

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=4 \sin 3 \pi x\)

4 step solution

Problem 24

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=\cot 3 x$$

4 step solution

Problem 24

Approximate to three decimal places. (a) csc \(43^{\circ} 40^{\prime}\) (b) sec 0.26

7 step solution

Problem 24

The peak of Mt. Fuji in Japan is approximately \(12,400\) feet high. A trigonometry student, several miles away, notes that the angle between level ground and the peak is \(30^{\circ} .\) Estimate the distance from the student to the point on level ground directly beneath the peak.

5 step solution

Problem 25

Verify the identity by transforming the left hand side into the right-hand side. $$\frac{1}{\cos (-x)}-\tan (-x) \sin (-x)=\cos x$$

6 step solution

Problem 25

A person flying a kite holds the string 4 feet above ground level. The string of the kite is taut and makes an angle of \(60^{\circ}\) with the horizontal (see the figure). Approximate the height of the kite above level ground if 500 feet of string is payed out. (IMAGE CAN NOT COPY)

4 step solution

Problem 25

Find the amplitude, the period, and the phase shift and sketch the graph of the equation. \(y=\frac{1}{2} \sin 2 \pi x\)

4 step solution

Problem 25

Find the period and sketch the graph of the equation. Show the asymptotes. $$y=2 \cot \left(2 x+\frac{\pi}{2}\right)$$

5 step solution

Problem 25

Approximate the acute angle \(\theta\) to the nearest (a) \(0.01^{\circ}\) and (b) \(1^{\prime}\) $$\cos \theta=0.8620$$

4 step solution

Problem 25

Stonehenge in Salisbury Plains, England, was constructed using solid stone blocks weighing over \(99,000\) pounds each. Lifting a single stone required 550 people, who pulled the stone up a ramp inclined at an angle of \(9^{\circ} .\) Approximate the distance that a stone was moved in order to raise it to a height of 30 feet.

5 step solution

Problem 25

Exer. \(25-28:\) Express the angle in terms of degrees, minutes, and seconds, to the nearest second. $$63.169^{\circ}$$

4 step solution

Problem 26

Verify the identity by transforming the left hand side into the right-hand side. $$\cot (-x) \cos (-x)+\sin (-x)=-\csc x$$

8 step solution

Problem 26

From a point 15 meters above level ground, a surveyor measures the angle of depression of an object on the ground at \(68^{\circ}\). Approximate the distance from the object to the point on the ground directly beneath the surveyor.

6 step solution

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