Chapter 8

Contemporary Precalculus · 88 exercises

Problem 1

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$A=44^{\circ}, B=22^{\circ}, a=6$$

4 step solution

Problem 1

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$A=40^{\circ}, b=10, c=7$$

6 step solution

Problem 1

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(2,3)$$

5 step solution

Problem 2

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$B=40^{\circ}, a=12, c=20$$

5 step solution

Problem 2

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(4,-2)$$

3 step solution

Problem 3

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$A=110^{\circ}, C=40^{\circ}, a=12$$

4 step solution

Problem 3

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$C=118^{\circ}, a=6, b=12$$

5 step solution

Problem 3

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(-3,7)$$

4 step solution

Problem 4

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$A=105^{\circ}, B=27^{\circ}, b=10$$

3 step solution

Problem 4

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$C=52.5^{\circ}, a=6.5, b=9$$

3 step solution

Problem 4

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(\sqrt{2}, \sqrt{3})$$

4 step solution

Problem 5

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$B=42^{\circ}, C=52^{\circ}, b=6$$

5 step solution

Problem 5

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$A=140^{\circ}, b=12, c=14$$

4 step solution

Problem 5

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(-3,-\sqrt{2})$$

3 step solution

Problem 6

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$A=67^{\circ}, C=28^{\circ}, a=9$$

4 step solution

Problem 6

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$B=25.4^{\circ}, a=6.8, c=10.5$$

3 step solution

Problem 6

Evaluate the trigonometric functions at the angle (in standard position) whose terminal side contains the given point. $$(3,-5)$$

2 step solution

Problem 7

Standard notation for triangle ABC is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve triangle ABC under the given conditions. $$A=102.3^{\circ}, B=36.2^{\circ}, a=16$$

3 step solution

Problem 7

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$C=78.6^{\circ}, a=12.1, b=20.3$$

4 step solution

Problem 8

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$A=118.2^{\circ}, b=16.5, c=10.7$$

3 step solution

Problem 8

The surveyor in Example 4 stands at the edge of another ravine, which is known to be 115 feet wide. She notes that the angle of depression from the edge she is standing on to the bottom of the oposite side is \(64.3^{\circ} .\) How deep is this ravine?

5 step solution

Problem 9

Solve the triangle. The Law of Cosines may be needed. $$b=12, c=20, B=70^{\circ}$$

5 step solution

Problem 9

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=7, b=3, c=5$$

6 step solution

Problem 10

Solve the triangle. The Law of Cosines may be needed. $$b=30, c=50, C=60^{\circ}$$

3 step solution

Problem 11

Solve the triangle. The Law of Cosines may be needed. $$a=15, b=12, B=20^{\circ}$$

3 step solution

Problem 11

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=16, b=30, c=32$$

5 step solution

Problem 11

A 20 -foot-long ladder leans on a wall of a building. The foot of the ladder makes an angle of \(50^{\circ}\) with the ground.How far above the ground does the top of the ladder touch the wall?

3 step solution

Problem 12

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=5.3, b=7.2, c=10$$

4 step solution

Problem 13

Solve the triangle. The Law of Cosines may be needed. $$a=5, c=12, A=102^{\circ}$$

4 step solution

Problem 13

A straight road leads from an ocean beach into the nearby hills. The road has a constant upward grade of \(3^{\circ} .\) After taking this road for one mile, how high above sea level (in feet) are you?(GRAPH CAN'T COPY)

4 step solution

Problem 13

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=7.2, b=6.5, c=11$$

4 step solution

Problem 14

Solve the triangle. The Law of Cosines may be needed. $$a=9, b=14, B=95^{\circ}$$

4 step solution

Problem 14

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=6.8, b=12.4, c=15.1$$

5 step solution

Problem 15

Solve the triangle. The Law of Cosines may be needed. $$b=12, c=10, C=56^{\circ}$$

5 step solution

Problem 15

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=12, b=16.5, c=20.6$$

6 step solution

Problem 16

Solve the triangle. The Law of Cosines may be needed. $$a=12.4, c=6.2, A=72^{\circ}$$

3 step solution

Problem 16

A wire from the top of a TV tower to the ground makes an angle of \(49.5^{\circ}\) with the ground and touches ground 225 feet from the base of the tower. How high is the tower?

6 step solution

Problem 16

Directions: Standard notation for triangle \(A B C\) is used throughout. Use a calculator and round off your answers to one decimal place at the end of the computation. Solve the triangle ABC under the given conditions. $$a=5.7, b=20.4, c=16.8$$

3 step solution

Problem 17

Find the angles of the triangle whose vertices are (0,0) (5,-2),(1,-4)

2 step solution

Problem 18

Solve the triangle. The Law of Cosines may be needed. $$a=30, b=40, A=30^{\circ}$$

5 step solution

Problem 18

The Seattle Space Needle casts a 225 -foot-long shadow. If the angle of elevation from the tip of the shadow to the top of the Space Needle is \(69.6^{\circ},\) how high is the Space Needle?

5 step solution

Problem 19

Solve the triangle. The Law of Cosines may be needed. $$b=4, c=10, A=75^{\circ}$$

7 step solution

Problem 19

In Example \(4,\) suppose that the angle between the two tracks is \(112^{\circ}\) and that the average speeds are 90 kilometers per hour for the first train and 55 kilometers per hour for the second train. How far apart are the trains after two hours and 45 minutes?

5 step solution

Problem 20

Solve the triangle. The Law of Cosines may be needed. $$a=50, c=80, C=45^{\circ}$$

5 step solution

Problem 20

From the top of a 130 -foot-high lighthouse, the angle of depression to a boat in Lake Erie is \(2.5^{\circ} .\) How far is the boat from the lighthouse?

6 step solution

Problem 21

Solve the triangle. The Law of Cosines may be needed. $$a=6, b=12, c=16$$

4 step solution

Problem 22

Alice is flying a kite. Her hand is three feet above ground level and is holding the end of a 300 -foot-long kite string, which makes an angle of \(57^{\circ}\) with the horizontal. How high is the kite above the ground?

4 step solution

Problem 23

Solve the triangle. The Law of Cosines may be needed. $$a=16.5, b=18.2, C=47^{\circ}$$

6 step solution

Problem 23

It is claimed that the Ohio Turnpike never has an uphill grade of more than \(3^{\circ} .\) How long must a straight uphill segment of the road be to allow a vertical rise of 450 feet?

5 step solution

Problem 24

Solve the triangle. The Law of Cosines may be needed. $$a=21, c=15.8, B=71^{\circ}$$

3 step solution

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