Midterm Review Part 1

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Trigonometry and Discrete Math

Midterm Exam 2016

Practice

Your preparation for the midterm exam should include reviewing your old tests and quizzes, going over your notes and projects, and completing this review. Good luck!

Trigonometry and Discrete Math

Midterm Exam Topics 2015-16

Unit 1: Trigonometry

Chapter 1- Trigonometry and Right Triangles

1.1

Basic Trig- Sine, Cosine, Tangent ratios of triangles SOH, CAH, TOA

Solve for missing sides

Solve for missing angles (inverse)

Angle of elevation and angle of depression word problems using sine, cosine, or tangent

1.2

Reciprocal Trig Functions- Secant, Cosecant, Cotangent ratios of triangles

1.3

Law of Sines sin⁑(𝐴) π‘Ž

Law of Cosines π‘Ž 2

= sin⁑(𝑩)

= 𝑏 2 𝑏

=

+ 𝑐 2 sin⁑(𝐢) 𝑐

− 2𝑏𝑐 ⋅ cos(𝐴)

1.4

Area of Oblique Triangles- Herons Formula (SSS) π΄π‘Ÿπ‘’π‘Ž = √𝑠(𝑠 − π‘Ž)(𝑠 − 𝑏)(𝑠 − 𝑐)⁑ where 𝑠 = π‘Ž+𝑏+𝑐

2

SAS Method π΄π‘Ÿπ‘’π‘Ž =

1

2 𝑏𝑐 ⋅ sin(𝐴)

Chapter 2- Trig in the Unit Circle

2.1

Convert Radians to Degrees- multiply by

180 πœ‹ πœ‹

Convert Degrees to Radians- multiply by

180

Coterminal angles- add or subtract 360 ⁰ or 2π

Reference Angles- always refer to the x-axis

2.2

Unit Circle- STUDY YOUR UNIT CIRCLE! (and how to find sine, cosine, tangent values)

2.4

Graphing Sine and Cosine, with transformations

Period = 2π/b

Starting/ ending points = set ( ) to 0 and to 2π

Make sure all graphs include 5 points along the x-axis and 3 points on the y-axis

2.5

Graphing tangent functions, with transformations

Tangent- period = π/b and

Intercepts = set ( ) to 0 and to π

Asymptotes = halfway between asymptotes

2.6

Graphing Cotangent functions, with transformations

Asymptotes = set ( ) to 0 and to π

Intercepts = halfway between asymptotes

2.7

Graphing Secant and Cosecant functions

Graph just like a sine or cosine, but add in additional parabola pieces between asymptotes

Chapter 3- Trig Identities

3.1

Simplify expressions by using mathematical operations and trig identities

3.2

Verify that a trig identity is correct- remember to work on the more complicated side

3.3

Solving Trig equations

Remember to refer to the unit circle at the last step

Sine and Cosine answers – must add +2nπ

Tangent answers – must add +nπ

Unit 2: Mathematical Modeling

Ferris Wheel Design Project

1.

What was the real world problem?

2.

What examples of trig did you use and what did you use it for?

3.

Connection to math modeling

What you will be given on the exam:

Law of Sines Formula

Law of Cosines Formula

Heron’s Formula (Area)

SAS Area Formula

The Unit Circle

47) The leaning tower of Pisa is tilted at an angle of 96 ⁰ from the ground. An observer standing 100m from the base of the tower measures the angle of elevation to be 30 ⁰ . Find the height of the tower using either law of sines or law of cosines.

48) After the hurricane, the small tree in the yard was leaning. To keep it from falling, a 6 foot strap was nailed into the ground 4 feet from the base of the tree. The strap was nailed to the tree 3.5 feet above the ground. What is the angle that the tree is leaning? Use the law of sines or the law of cosines to solve.

49) The area of a triangular room is 140 feet

2

. The length of side AB is 18 feet and angle B is 75 ⁰ . Find the length of side BC.

50) A triangular field is surveyed. The length of one side of the field measured 365 meters and another side was

267 meters. The third side measured 308 meters. Find the area of the farmer’s field.

Simplify the following trigonometric expressions using all identities. π‘ π‘–π‘›πœƒ

51)

1−π‘π‘œπ‘ πœƒ

+ π‘ π‘–π‘›πœƒ

1+π‘π‘œπ‘ πœƒ

52) ⁑ π‘ π‘–π‘›πœƒ π‘‘π‘Žπ‘›πœƒ

+ π‘π‘œπ‘ πœƒ π‘π‘œπ‘‘πœƒ

Verify the following trigonometric equations using all trig identities.

53) π‘‘π‘Žπ‘› 2 πœƒ(1 − 𝑠𝑖𝑛 2 πœƒ) = 𝑠𝑖𝑛 2 πœƒ 54) β‘π‘π‘œπ‘‘πœƒπ‘ π‘’π‘πœƒπ‘ π‘–π‘›πœƒ = 1

1

55)

1−π‘ π‘–π‘›πœƒ

1

+

1+π‘ π‘–π‘›πœƒ

= 2𝑠𝑒𝑐 2 πœƒ 56) β‘π‘π‘ π‘πœƒ − π‘π‘œπ‘ πœƒπ‘π‘œπ‘‘πœƒ = π‘ π‘–π‘›πœƒ

Solve the following trigonometric equations for the radian measure using the unit circle.

57) 7π‘π‘œπ‘‘π‘₯ − √3 = 4π‘π‘œπ‘‘π‘₯ 58) 2 = 4π‘π‘œπ‘  2 π‘₯ + 1

47) Set Up: 𝑠𝑖𝑛30 π‘₯

= 𝑠𝑖𝑛54

(Solve for 3

100 rd angle first, then use law of sines) x = 61.8 m

48) Set Up: (6) 2 = (3.5) 2 + (4) 2 − 2(3.5)(4)π‘π‘œπ‘ πœƒ

θ = 106.3

⁰

49) Set Up: 150 =

1

(18)π‘Ž(𝑠𝑖𝑛75)

2

Length of a = 16 feet

50) Semi perimeter = 470

Set Up: 𝐴 = √470(470 − 365)(470 − 308)(470 − 267)

Area = 40,285.5 meters

2

(1+π‘π‘œπ‘ πœƒ)π‘ π‘–π‘›πœƒ

51)

(1+π‘π‘œπ‘ πœƒ)1−π‘π‘œπ‘ πœƒ

(π‘π‘œπ‘‘πœƒ)π‘ π‘–π‘›πœƒ

52)

(π‘π‘œπ‘‘πœƒ)π‘‘π‘Žπ‘›πœƒ

+

+ π‘ π‘–π‘›πœƒ(1−π‘π‘œπ‘ πœƒ)

1+π‘π‘œπ‘ πœƒ(1−π‘π‘œπ‘ πœƒ)

→ π‘ π‘–π‘›πœƒ+π‘ π‘–π‘›πœƒπ‘π‘œπ‘ πœƒ+π‘ π‘–π‘›πœƒ−π‘ π‘–π‘›πœƒπ‘π‘œπ‘ πœƒ

1−π‘π‘œπ‘ πœƒ+π‘π‘œπ‘ πœƒ−π‘π‘œπ‘  2 πœƒ

2π‘ π‘–π‘›πœƒ

1−π‘π‘œπ‘  2 πœƒ

2π‘ π‘–π‘›πœƒ 𝑠𝑖𝑛 2 πœƒ

2

→ π‘ π‘–π‘›πœƒ

→ 2π‘π‘ π‘πœƒ π‘π‘œπ‘ πœƒ(π‘‘π‘Žπ‘›πœƒ) π‘π‘œπ‘‘πœƒ(π‘‘π‘Žπ‘›πœƒ)

→ π‘π‘œπ‘ πœƒ π‘ π‘–π‘›πœƒ

βˆ™ π‘ π‘–π‘›πœƒ

+

1 π‘π‘œπ‘ πœƒ

βˆ™

1 π‘ π‘–π‘›πœƒ π‘π‘œπ‘ πœƒ π‘π‘œπ‘‘πœƒπ‘‘π‘Žπ‘›πœƒ

→ π‘π‘œπ‘ πœƒ+π‘ π‘–π‘›πœƒ

1

→ π‘π‘œπ‘ πœƒ + π‘ π‘–π‘›πœƒ

53) π‘‘π‘Žπ‘› 2 πœƒ(1 − 𝑠𝑖𝑛 2 πœƒ)⁑ → π‘‘π‘Žπ‘› 2 πœƒ(π‘π‘œπ‘  2 𝑠𝑖𝑛

2 πœƒ) → π‘π‘œπ‘  πœƒ

2 πœƒ

βˆ™ π‘π‘œπ‘ 

2 πœƒ

→ 𝑠𝑖𝑛

1

2 πœƒ

54) π‘π‘œπ‘‘πœƒπ‘ π‘’π‘πœƒπ‘ π‘–π‘›πœƒ → π‘π‘œπ‘ πœƒ π‘ π‘–π‘›πœƒ

(1+π‘ π‘–π‘›πœƒ)1

55)

(1+π‘ π‘–π‘›πœƒ)1−π‘ π‘–π‘›πœƒ

+

βˆ™

1 π‘π‘œπ‘ πœƒ

1(1−π‘ π‘–π‘›πœƒ)

βˆ™ π‘ π‘–π‘›πœƒ

1

1+π‘ π‘–π‘›πœƒ(1−π‘ π‘–π‘›πœƒ)

→ 1

1+π‘ π‘–π‘›πœƒ+1−π‘ π‘–π‘›πœƒ

1−π‘ π‘–π‘›πœƒ+π‘ π‘–π‘›πœƒ−𝑠𝑖𝑛 2 πœƒ

2

1−𝑠𝑖𝑛 2 πœƒ

2

→ π‘π‘œπ‘  2 πœƒ

→ 2𝑠𝑒𝑐 2 πœƒ

1

56) π‘π‘ π‘πœƒ − π‘π‘œπ‘ πœƒπ‘π‘œπ‘‘πœƒ → π‘ π‘–π‘›πœƒ πœ‹

57) π‘‘π‘Žπ‘›π‘₯ = √3 → π‘₯ =

3

− π‘π‘œπ‘ πœƒ

1

+ π‘›πœ‹, π‘₯ =

58) π‘π‘œπ‘ π‘₯ = ±

1

2

→ π‘₯ = πœ‹

3

+ 2π‘›πœ‹, π‘₯ =

βˆ™

4πœ‹

3 π‘π‘œπ‘ πœƒ π‘ π‘–π‘›πœƒ

1

→ π‘ π‘–π‘›πœƒ

2πœ‹

3

+ π‘›πœ‹

+ 2π‘›πœ‹, π‘₯ = π‘π‘œπ‘ 

2 π‘ π‘–π‘›πœƒ πœƒ

1−π‘π‘œπ‘  π‘ π‘–π‘›πœƒ

2 πœƒ

→ 𝑠𝑖𝑛

2 π‘ π‘–π‘›πœƒ πœƒ

→ π‘ π‘–π‘›πœƒ

4πœ‹

3

+ 2π‘›πœ‹, π‘₯ =

5πœ‹

3

+ 2π‘›πœ‹

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