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Wave Riders • Lesson • Lenny.com
Wave Riders A mini-lesson on graphing, analyzing, and modeling transformed sine and cosine trigonometric waves. Students learn to identify key parameters (amplitude, period, phase shift, midline) from equations and graphs, and apply them to periodic real-world scenarios.
AE Aysenur Ersoy
Wave Riders Guided Notes
Guided notes packet (3 pages) teaching transformed sine and cosine waves. Uses robust, high-fidelity HTML/CSS math formatting to ensure flawless rendering. Includes standard equations, key variables, an annotated graph diagram, graphing guides, and a step-by-step real-world tides modeling guide.
Wave Riders Practice Worksheet
A 3-page student practice worksheet designed to complement the guided notes. Features structured exercises for parameter identification, equation matching, wave sketching, graph-to-equation translation, and two real-world modeling scenarios (Ferris Wheel and Seasonal Temperature).
Wave Riders Practice Worksheet
A 3-page student practice worksheet designed to complement the guided notes. Features structured exercises for parameter identification, equation matching, wave sketching, graph-to-equation translation, and two real-world modeling scenarios (Ferris Wheel and Seasonal Temperature).
Wave Riders Teacher Key
A 3-page comprehensive Teacher Answer Key containing complete solutions, calculated steps, matching keys, and fully labeled mathematical answers for the Wave Riders units.
Wave Riders Teacher Key
A 3-page comprehensive Teacher Answer Key containing complete solutions, calculated steps, matching keys, and fully labeled mathematical answers for the Wave Riders units.
Wave Riders A mini-lesson on graphing, analyzing, and modeling transformed sine and cosine trigonometric waves. Students learn to identify key parameters (amplitude, period, phase shift, midline) from equations and graphs, and apply them to periodic real-world scenarios.
AE Aysenur Ersoy
Wave Riders Guided Notes Honors Algebra II / Precalculus
Wave Riders: Guided Notes
Anatomy & Parameters of Transformed Trigonometric Waves
Name: ______________________ Date: _________
Class: _________________
Standard Equations of Trigonometric Waves
Ocean waves, light, sound, tides, and Ferris wheels all exhibit periodic behavior. We model these repeating patterns by transforming the parent sine and cosine functions.
Sine Wave model
y = a • sin(b(x − h)) + k
Cosine Wave model
y = a • cos(b(x − h)) + k
Key Variables & Mathematical Formulas
Complete the definitions and formulas below to unlock the wave transformation toolkit:
Letter & Variable What it Does (Physical Effect) Calculation & Formula Rule a (Amplitude) Controls the vertical stretch/compression. Wave height from the ________________. a = max − min __________
(Always positive distance value) |
| b (Frequency) | Controls horizontal stretch/compression.
Number of cycles in a __________ interval. | b =
__________ Period
|
| Period | The length of __________ complete cycle.
How long it takes the wave to repeat. | Period =
2π __________
|
| h (Phase Shift) | Controls horizontal translation.
Shift Left: (x + h) | Shift __________: (x − h) | Initial start point of the pattern cycle. |
| k (Vertical Shift) | Controls vertical translation.
Defines the center/________________ of the wave. | k =
max + min __________
Midline line equation: y = k |
Visual Anatomy of a Sine Wave
Label the diagram below using the keywords: Amplitude , Midline (y=k) , Period , and Phase Shift (h) .
① _______________________
② _______________________
③ _______________________
④ _______________________
UNIT 5: TRIGONOMETRIC FUNCTIONS PAGE 1 OF 3 LENNY LEARNING SYSTEMS © 2026
Part II: Guided Practice
Graphing from Wave Equations
Drafting wave structures systematically using the Five-Point Method
Wave Riders Unit Topic 5.2
1 Vertical Bounds
Sketch the midline y = k. Mark the boundaries at y = k ± a.
2 Cycle Range
Start at shift h. Add the Period to locate cycle end.
3 The 5 Key Points
Divide period into 4 quarters. Plot start, mid, end, max/min.
Guided Walkthrough: Graphing y = 2·sin(2(x − π/4)) + 1
Sine Wave
Calculate Parameters:
Amplitude a = _______
Frequency b = _______
Period =
2π b
= _______
Phase Shift h = _______ (________)
Vertical Shift k = _______
Critical coordinates:
Midline: y = _______
Maximum: _______ | Minimum: _______
Horizontal bounds of wave:
Starts at _______ | Ends at _______
Quarter Width =
Period 4
= _______
Point Position Start (x = h) 1st Quarter Midpoint 3rd Quarter End (x = h + Pd) x-value __________ __________ __________ __________ __________ Pattern Behavior Midline Maximum Midline Minimum Midline y-value __________ __________ __________ __________ __________
Grid Setup & Wave Sketch
Step 1: Sketch midline. Step 2: Scale and label the axes. Step 3: Plot the 5 key points and connect with a smooth, curved wave.
y=4 y=3 y=2 y=1 0 y=-1 y=-2 π/4 π/2 3π/4 π 5π/4 3π/2 7π/4
UNIT 5: TRIGONOMETRIC FUNCTIONS PAGE 2 OF 3 LENNY LEARNING SYSTEMS © 2026
Part III: Applications
Writing Equations & Real-World Modeling
Extracting trigonometric variables from mathematical graphs and real-life rhythms
Wave Riders Unit Topic 5.3
Section 1: Working Backwards (From Graph to Equation)
Given Graph:
3 1 y=-1 0 -3 π/2 π
Wave cycle from x = 0 to π
Follow the formulas to build the cosine/sine equation:
1. Find Peak and Trough:
Max = _______ | Min = _______
2. Midline (Vertical Shift, k):
k =
Max + Min 2
= _______
3. Amplitude (a):
a =
Max − Min 2
= _______
4. Period & Frequency (b):
Cycle length Period = _______ | b =
2π Period
= _______
Completed Sine Model (with h = 0):
y = ________________________________________
Section 2: Ocean Harbor Tides Scenario
The Pier Deep-Water Dock: The ocean water depth fluctuates periodically. At high tide (midnight, t = 0), the depth reaches a maximum of 16 meters . Low tide occurs exactly 6 hours later, at a minimum depth of 4 meters .
1. Identify Key Details:
Maximum Depth = ______ m
Minimum Depth = ______ m
2. Find the Midline (k):
k =
Max + Min 2
= ______ m
(This is average water depth)
3. Find the Amplitude (a):
a =
Max − Min 2
= ______ m
(Max deviation from average)
4. Find the Period & Frequency (b):
Time from High to Low = 6 hours.
Full cycle Period = ______ hours
Calculate b =
2π Period
= ______
5. Formulate the Cosine Function Model
Since the depth cycle starts at high tide (maximum height) at t = 0, we model this using a standard positive cosine function with phase shift h = 0: d(t) = a · cos(b · t) + k.
d(t) = _________________________________________
UNIT 5: TRIGONOMETRIC FUNCTIONS PAGE 3 OF 3 LENNY LEARNING SYSTEMS © 2026
Wave Riders Practice Worksheet Honors Algebra II / Precalculus
Wave Riders: Practice Worksheet
Independent Practice: Identifying Features & Sketching Curves
Name: ______________________ Date: _________
Class: _________________
Section 1: Finding Parameters from Equations
Identify the Amplitude, Frequency, Period, Phase Shift (include direction), and Midline equation for each wave:
\( y = 4\sin(2x) - 3 \)
Amplitude \( a \): _________
Frequency \( b \): _________
Period: _________
Phase Shift \( h \): _________
Midline Equation: __________________
\( y = -3\cos(x - \pi/3) + 1 \)
Amplitude \( a \): _________
Frequency \( b \): _________
Period: _________
Phase Shift \( h \): _________
Midline Equation: __________________
\( y = \frac{1}{2}\sin(4(x + \pi/2)) + 5 \)
Amplitude \( a \): _________
Frequency \( b \): _________
Period: _________
Phase Shift \( h \): _________
Midline Equation: __________________
\( y = 2\cos(\pi(x - 1)) - 6 \)
Amplitude \( a \): _________
Frequency \( b \): _________
Period: _________
Phase Shift \( h \): _________
Midline Equation: __________________
Section 2: Parameter Matching Challenge
Write the letter of the equation on the left that matches the correct description on the right (answers do not repeat):
A \( y = 3\sin(2x) + 4 \)
B \( y = 2\cos(4x) + 3 \)
C \( y = 4\sin(\pi(x + 1)) - 2 \)
D \( y = 5\cos(x - \pi) + 2 \)
_____
Has a period of \( \pi/2 \) and midline \( y=3 \).
_____
Has an amplitude of 5 and shifted right by \( \pi \).
_____
Has a period of \( \pi \) and midline \( y=4 \).
_____
Has a period of 2 and midline \( y=-2 \).
Section 3: Sketching transformed curves
Task: Identify parameters and sketch one complete period cycle of \( y = 3\sin(2x) - 1 \) on the provided coordinate grid below.
Setup Reference:
• Midline \( k = \) _________
• Amplitude \( a = \) _________
• Max/Min = _____ / _____
• Period \( = \) _________
Wave Riders Practice Worksheet Honors Algebra II / Precalculus
Wave Riders: Practice Worksheet
Independent Practice: Identifying Features & Sketching Curves
Name: ______________________ Date: _________
Class: _________________
Section 1: Finding Parameters from Equations
Identify the Amplitude, Frequency, Period, Phase Shift (include direction), and Midline equation for each wave:
y = 4·sin(2x) − 3
Amplitude a: _________
Frequency b: _________
Period: _________
Phase Shift h: _________
Midline Equation: __________________
y = −3·cos(x − π/3) + 1
Amplitude a: _________
Frequency b: _________
Period: _________
Phase Shift h: _________
Midline Equation: __________________
y = ½·sin(4(x + π/2)) + 5
Amplitude a: _________
Frequency b: _________
Period: _________
Phase Shift h: _________
Midline Equation: __________________
y = 2·cos(π(x − 1)) − 6
Amplitude a: _________
Frequency b: _________
Period: _________
Phase Shift h: _________
Midline Equation: __________________
Section 2: Parameter Matching Challenge
Write the letter of the equation on the left that matches the correct description on the right (answers do not repeat):
A y = 3·sin(2x) + 4
B y = 2·cos(4x) + 3
C y = 4·sin(π(x + 1)) − 2
D y = 5·cos(x − π) + 2
_____
Has a period of π/2 and midline y=3.
_____
Has an amplitude of 5 and shifted right by π.
_____
Has a period of π and midline y=4.
_____
Has a period of 2 and midline y=−2.
Section 3: Sketching transformed curves
Task: Identify parameters and sketch one complete period cycle of y = 3·sin(2x) − 1 on the provided coordinate grid below.
Setup Reference:
• Midline k = _________
• Amplitude a = _________
• Max/Min = _____ / _____
• Period = _________
• Start/End x: 0 / _________
Quarter points:
Q1:_____ | Q2:_____ | Q3:_____
y=3 y=2 y=1 0 y=-1 y=-2 y=-3 ____ ____ ____ ____
Wave Riders Teacher Key Teacher Resource • Answer Key
Wave Riders Master Key (Page 1)
Anatomy, Parameter Formulas, and Equation Matching Solutions
SOLUTIONS Classroom Guide
1. Guided Notes (Page 1) Blanks Solutions
• \( a \) (Amplitude) Blanks: height from the midline / center | Formula: \( a = \frac{\text{max} - \text{min}}{\text{\underline{\textbf{2}}}} \).
• \( b \) (Frequency) Blanks: cycles in a \( 2\pi \) interval | Formula: \( b = \frac{\text{\underline{\textbf{\( 2\pi \) \}}}}{\text{Period}} \).
• Period Blanks: length of one complete cycle | Formula: \( \text{Period} = \frac{2\pi}{\text{\underline{\textbf{b}}}} \).
• \( h \) (Phase Shift) Blanks: Shift Left is \( (x+h) \) | Shift Right is \( (x-h) \).
• \( k \) (Vertical Shift) Blanks: defines center/midline of wave | Formula: \( k = \frac{\text{max} + \text{min}}{\text{\underline{\textbf{2}}}} \).
Visual Diagram Labels Key:
① Midline Equation: y = k
② Vertical Height: Amplitude (a)
③ Horizontal Length: Period
④ Shift Distance: Phase Shift (h)
2. Worksheet (Page 1) Section 1 & 2 Answers
\( y = 4\sin(2x) - 3 \)
a = 4 | b = 2
Period = 2π/2 = π
Phase Shift: 0
Midline: y = -3
\( y = -3\cos(x - \pi/3) + 1 \)
a = 3 (dist. is positive) | b = 1
Period = 2π
Phase Shift: π/3 Right
Midline: y = 1
\( y = \frac{1}{2}\sin(4(x + \pi/2)) + 5 \)
a = 0.5 | b = 4
Period = 2π/4 = π/2
Phase Shift: π/2 Left
Midline: y = 5
\( y = 2\cos(\pi(x - 1)) - 6 \)
a = 2 | b = π
Period = 2π/π = 2
Phase Shift: 1 Right
Midline: y = -6
Section 2: Matching Order (Top to Bottom):
Row 1: B
Row 2: D
Row 3: A
Row 4: C
Section 3 Sketch Setup Values:
For \( y = 3\sin(2x) - 1 \): Midline \( y = -1 \). Max = 2, Min = -4. Period = \( \pi \). Starts at 0, quarters are \(\pi/4, \pi/2, 3\pi/4, \pi\) . Critical 5 coordinates are: \( (0, -1) \to (\pi/4, 2) \to (\pi/2, -1) \to (3\pi/4, -4) \to (\pi, -1) \)
UNIT 5: ANSWER KEYS PAGE 1 OF 3 LENNY LEARNING SYSTEMS © 2026
Teacher Resource • Answer Key
Wave Riders Teacher Key Teacher Resource • Answer Key
Wave Riders Master Key (Page 1)
Anatomy, Parameter Formulas, and Equation Matching Solutions
SOLUTIONS Classroom Guide
1. Guided Notes (Page 1) Blanks Solutions
• a (Amplitude) Blanks: height from the midline / center | Formula: 2.
• b (Frequency) Blanks: cycles in a 2π interval | Formula: 2π.
• Period Blanks: length of one complete cycle | Formula: b.
• h (Phase Shift) Blanks: Shift Left is (x + h) | Shift Right is (x − h).
• k (Vertical Shift) Blanks: defines center/midline of wave | Formula: 2.
Visual Diagram Labels Key:
① Midline Equation: y = k
② Vertical Height: Amplitude (a)
③ Horizontal Length: Period
④ Shift Distance: Phase Shift (h)
2. Worksheet (Page 1) Section 1 & 2 Answers
y = 4·sin(2x) − 3
Amplitude a = 4 | b = 2
Period = 2π/2 = π
Phase Shift: 0
Midline: y = -3
y = −3·cos(x − π/3) + 1
Amplitude a = 3 | b = 1
Period = 2π
Phase Shift: π/3 Right
Midline: y = 1
y = ½·sin(4(x + π/2)) + 5
Amplitude a = 0.5 | b = 4
Period = 2π/4 = π/2
Phase Shift: π/2 Left
Midline: y = 5
y = 2·cos(π(x − 1)) − 6
Amplitude a = 2 | b = π
Period = 2π/π = 2
Phase Shift: 1 Right
Midline: y = -6
Section 2: Matching Order (Top to Bottom):
Row 1: B
Row 2: D
Row 3: A
Row 4: C
Section 3 Sketch Setup Values:
For y = 3·sin(2x) − 1: Midline y = −1. Max = 2, Min = −4. Period = π. Starts at 0, quarters are π/4, π/2, 3π/4, π . Critical 5 coordinates are: (0, −1) → (π/4, 2) → (π/2, −1) → (3π/4, −4) → (π, −1)
UNIT 5: ANSWER KEYS PAGE 1 OF 3 LENNY LEARNING SYSTEMS © 2026
Teacher Resource • Answer Key
Wave Riders Master Key (Page 2)
Graphing Calculations and Graphic Walkthrough Solutions
SOLUTIONS Classroom Guide
1. Guided Walkthrough: Graphing y = 2·sin(2(x − π/4)) + 1
Calculated Parameters:
Amplitude a = 2
• Start/End \( x \): 0 / _________
• Quarter points \( x \):
Q1: ______ | Q2: ______ | Q3: ______
y=3 y=2 y=1 0 y=-1 y=-2 y=-3 ____ ____ ____ ____
WAVE RIDERS: WORKSHEET PAGE 1 OF 3 LENNY LEARNING SYSTEMS © 2026
Part II: Graph-to-Equation Practice
Translating Wave Graphs to Equations Deconstructing graphical waves into mathematical parameters
Topic 5.2 Practice Workspace
Directions: Analyze the graph of each transformed wave carefully. Determine its maximum/minimum heights, midline equation, amplitude, period, and frequency parameter \( b \). Then write the final equation.
Problem 5: Analyze and Model (Sine Wave, no Phase Shift)
Step 1: Max = _______ | Min = _______
Step 2: Midline \( k = \frac{\text{Max}+\text{Min}}{2} = \) _______
Step 3: Amplitude \( a = \frac{\text{Max}-\text{Min}}{2} = \) _______
Step 4: Period length = _______ | \( b = \frac{2\pi}{\text{Period}} = \) _______
Final Sine Model (h = 0):
\( y = \) _________________________________
Problem 6: Analyze and Model (Cosine Wave, starting at Peak)
Step 1: Max = _______ | Min = _______
Step 2: Midline \( k = \frac{\text{Max}+\text{Min}}{2} = \) _______
Step 3: Amplitude \( a = \frac{\text{Max}-\text{Min}}{2} = \) _______
Step 4: Period length = _______ | \( b = \frac{2\pi}{\text{Period}} = \) _______
Final Cosine Model (h = 0):
\( y = \) _________________________________
WAVE RIDERS: WORKSHEET PAGE 2 OF 3 LENNY LEARNING SYSTEMS © 2026
Part III: Real-World Scenarios
Modeling Periodic Environments Drafting dynamic trigonometric models for circular and seasonal structures
Topic 5.3 Practice Applied Math
Problem 7: The Giant Ocean Star Ferris Wheel A tourist boards a massive Ferris wheel next to the ocean. The wheel has a diameter of 40 meters . The boarding platform is 2 meters above the ground. Once boarding is complete, the wheel spins and takes exactly 12 minutes to make one full rotation. Let \( t = 0 \) represent the boarding time at the lowest position.
Min rider height = ______ m
Max rider height = ______ m
Vertical Midline \( k \) = ______ m
Amplitude \( a \) = ______ m
Rotation Period = ______ min
Frequency \( b = \frac{2\pi}{\text{Period}} = \) ______
C. Formulate the Trigonometric Equation Model
Hint: The rider starts at the lowest point at \( t=0 \). Therefore, a negative cosine model , \( h(t) = -a \cdot \cos(b \cdot t) + k \), perfectly represents the path without a horizontal phase shift!
\( h(t) = \) _________________________________________________
Problem 8: Climate Cycles in Surf City The average monthly temperature of Surf City fluctuates periodically throughout the year. The average low temperature is 42°F in January (\( t = 1 \)), and the average high temperature is 86°F in July (\( t = 7 \)). A full year's cycle is exactly 12 months .
A. Temperature Midline & Amp:
Average Midline \( k \):
\( k = \frac{86 + 42}{2} = \) _______ °F
Amplitude \( a \):
\( a = \frac{86 - 42}{2} = \) _______ °F
Temperature Cycle = _______ months
Calculate Frequency \( b \):
\( b = \frac{2\pi}{\text{Period}} = \) _______
C. Build a Transformed Model
Let's build a weather cycle starting at its lowest point in January (\( t = 1 \)). We can model this by shifting a negative cosine model right by 1 month (\( h = 1 \)) !
Write your final Cosine wave model shifted right by 1 month (\( h=1 \)):
\( T(t) = -a \cdot \cos(b(t - 1)) + k \Rightarrow \) T(t) = _______________________________
WAVE RIDERS: WORKSHEET PAGE 3 OF 3 LENNY LEARNING SYSTEMS © 2026
WAVE RIDERS: WORKSHEET PAGE 1 OF 3 LENNY LEARNING SYSTEMS © 2026
Part II: Graph-to-Equation Practice
Translating Wave Graphs to Equations Deconstructing graphical waves into mathematical parameters
Topic 5.2 Practice Workspace
Directions: Analyze the graph of each transformed wave carefully. Determine its maximum/minimum heights, midline equation, amplitude, period, and frequency parameter b. Then write the final equation.
Problem 5: Analyze and Model (Sine Wave, no Phase Shift)
Step 1: Max = _______ | Min = _______
Step 4: Period = _______ | b =
Final Sine Model (h = 0):
y = _________________________________
Problem 6: Analyze and Model (Cosine Wave, starting at Peak)
Step 1: Max = _______ | Min = _______
Step 4: Period = _______ | b =
Final Cosine Model (h = 0):
y = _________________________________
WAVE RIDERS: WORKSHEET PAGE 2 OF 3 LENNY LEARNING SYSTEMS © 2026
Part III: Real-World Scenarios
Modeling Periodic Environments Drafting dynamic trigonometric models for circular and seasonal structures
Topic 5.3 Practice Applied Math
Problem 7: The Giant Ocean Star Ferris Wheel A tourist boards a massive Ferris wheel next to the ocean. The wheel has a diameter of 40 meters . The boarding platform is 2 meters above the ground. Once boarding is complete, the wheel spins and takes exactly 12 minutes to make one full rotation. Let t = 0 represent the boarding time at the lowest position.
Min rider height = ______ m
Max rider height = ______ m
Vertical Midline k = ______ m
Rotation Period = ______ min
C. Formulate the Trigonometric Equation Model
Hint: The rider starts at the lowest point at t=0. Therefore, a negative cosine model , h(t) = −a · cos(b·t) + k, perfectly represents the path without a horizontal phase shift!
h(t) = _________________________________________________
Problem 8: Climate Cycles in Surf City The average monthly temperature of Surf City fluctuates periodically throughout the year. The average low temperature is 42°F in January (t = 1), and the average high temperature is 86°F in July (t = 7). A full year's cycle is exactly 12 months .
A. Temperature Midline & Amp:
Temperature Cycle = _______ months
Calculate Frequency b:
b =
C. Build a Transformed Model
Let's build a weather cycle starting at its lowest point in January (t = 1). We can model this by shifting a negative cosine model right by 1 month (h = 1) !
Write your final Cosine wave model shifted right by 1 month (h=1):
T(t) = −a · cos(b(t − 1)) + k ⇒ T(t) = _______________________________
WAVE RIDERS: WORKSHEET PAGE 3 OF 3 LENNY LEARNING SYSTEMS © 2026
Wave Riders Master Key (Page 2) Graphing Calculations and Graphic Walkthrough Solutions
SOLUTIONS Classroom Guide
1. Guided Walkthrough: Graphing \( y = 2\sin(2(x - \frac{\pi}{4})) + 1 \) Phase Shift \( h \) = \(\pi/4\) Right
Vertical Shift \( k \) = 1
Horizontal Bounds: \(\pi/4\) to \(5\pi/4\)
Critical 5-Points Coordinate Table:
2. Worksheet (Page 2) Problem 5 & 6 Solutions Problem 5 Sine Graph Answers: y = 3sin(x) + 2
• Step 1 Peak/Trough: Max = 5 | Min = -1
• Step 2 Midline (k): (5 + -1)/2 = 2 (y = 2)
• Step 3 Amplitude (a): (5 - -1)/2 = 3
• Step 4 Period & b: Pd = 2π | b = 2π/2π = 1
Problem 6 Cosine Graph Answers: y = 2cos(2x) + 1
• Step 1 Peak/Trough: Max = 3 | Min = -1
• Step 2 Midline (k): (3 + -1)/2 = 1 (y = 1)
• Step 3 Amplitude (a): (3 - -1)/2 = 2
• Step 4 Period & b: Pd = π | b = 2π/π = 2
UNIT 5: ANSWER KEYS PAGE 2 OF 3 LENNY LEARNING SYSTEMS © 2026
Teacher Resource • Answer Key
Wave Riders Master Key (Page 3) Applied Real-World trigonometric Modeling Solutions
SOLUTIONS Classroom Guide
1. Guided Notes Page 3: Harbor Tides Model Solution • Max Depth = 16 meters | Min Depth = 4 meters
• Midline Average Depth \( k = \frac{16 + 4}{2} = \) 10 meters
• Amplitude Fluctuation \( a = \frac{16 - 4}{2} = \) 6 meters
• Time High-to-Low is 6 hrs \(\to\) Full Cycle Period = 12 hours
• Frequency Coefficient \( b = \frac{2\pi}{12} = \) \(\pi/6\)
Final Tides Equation: \( d(t) = 6\cos(\frac{\pi}{6}t) + 10 \)
2. Practice Worksheet Problem 7: Ocean Star Ferris Wheel Solution • Height Bounds: Min height = 2 m | Max height = 2 + 40 = 42 m
• Vertical Center Midline \( k = \frac{42 + 2}{2} = \) 22 m
• Radius Amplitude \( a = \frac{42 - 2}{2} = \) 20 m
• Rotation Period = 12 minutes
• Frequency \( b = \frac{2\pi}{12} = \) \(\pi/6\)
Final Ferris Wheel Equation: \( h(t) = -20\cos(\frac{\pi}{6}t) + 22 \)
3. Practice Worksheet Problem 8: Climate Cycles in Surf City Solution • Average Temperatures: Min = 42°F (January) | Max = 86°F (July)
• Yearly Temperature Midline \( k = \frac{86 + 42}{2} = \) 64°F
• Temperature Amplitude \( a = \frac{86 - 42}{2} = \) 22°F
• Cycle Period = 12 months | Frequency \( b = \frac{2\pi}{12} = \) \(\pi/6\)
• Phase Shift: Minimum occurs at January (\( t = 1 \)), shifting negative cosine right by 1.
Final Temperature Equation: \( T(t) = -22\cos(\frac{\pi}{6}(t - 1)) + 64 \)
UNIT 5: ANSWER KEYS PAGE 3 OF 3 LENNY LEARNING SYSTEMS © 2026
Phase Shift h = π/4 (Right)
Horizontal Bounds: π/4 to 5π/4
Critical 5-Points Coordinate Table:
2. Worksheet (Page 2) Problem 5 & 6 Solutions Problem 5 Sine Graph Answers: y = 3·sin(x) + 2
• Step 1 Peak/Trough: Max = 5 | Min = -1
• Step 2 Midline (k): (5 + -1)/2 = 2 (y = 2)
• Step 3 Amplitude (a): (5 − -1)/2 = 3
• Step 4 Period & b: Pd = 2π | b = 1
Problem 6 Cosine Graph Answers: y = 2·cos(2x) + 1
• Step 1 Peak/Trough: Max = 3 | Min = -1
• Step 2 Midline (k): (3 + -1)/2 = 1 (y = 1)
• Step 3 Amplitude (a): (3 − -1)/2 = 2
• Step 4 Period & b: Pd = π | b = 2
UNIT 5: ANSWER KEYS PAGE 2 OF 3 LENNY LEARNING SYSTEMS © 2026
Teacher Resource • Answer Key
Wave Riders Master Key (Page 3) Applied Real-World trigonometric Modeling Solutions
SOLUTIONS Classroom Guide
1. Guided Notes Page 3: Harbor Tides Model Solution • Max Depth = 16 meters | Min Depth = 4 meters
• Midline Average Depth k = (16+4)/2 = 10 meters
• Amplitude Fluctuation a = (16-4)/2 = 6 meters
• Time High-to-Low is 6 hrs → Full Cycle Period = 12 hours
• Frequency Coefficient b = 2π/12 = π/6
Final Tides Equation: d(t) = 6·cos((π/6)t) + 10
2. Practice Worksheet Problem 7: Ocean Star Ferris Wheel Solution • Height Bounds: Min height = 2 m | Max height = 2 + 40 = 42 m
• Vertical Center Midline k = (42+2)/2 = 22 m
• Radius Amplitude a = (42-2)/2 = 20 m
• Rotation Period = 12 minutes
• Frequency b = 2π/12 = π/6
Final Ferris Wheel Equation: h(t) = −20·cos((π/6)t) + 22
3. Practice Worksheet Problem 8: Climate Cycles Solution • Average Temperatures: Min = 42°F (Jan) | Max = 86°F (July)
• Yearly Temperature Midline k = (86+42)/2 = 64°F
• Temperature Amplitude a = (86-42)/2 = 22°F
• Cycle Period = 12 months | Frequency b = π/6
• Phase Shift: Minimum occurs in Jan (t=1), shifting negative cosine right by 1.
Final Temperature Equation: T(t) = −22·cos((π/6)(t − 1)) + 64
UNIT 5: ANSWER KEYS PAGE 3 OF 3 LENNY LEARNING SYSTEMS © 2026